troubleshooting hdmi systems - quantumdata

Troubleshooting HDMI® Systems: Diagnostic Problems with the Quantum Data

780/780A Test Instrument

Neal Kendall

Quantum Data

[email protected]

Causes Callbacks

Requires More Time

% of Installs with HDMI

% of Techs Removing Devices

% of Simplified System Designs

Problem Types Addressed in this Training Class

Connection sequence—protocol sequence of events between a source and sink (handshaking) upon turn-up or connection—involves the following functions:

Connection detection (Hot Plug) – a hot plug problem usually results in no video & audio.

Plug and Play (EDID) – an EDID problem usually results in wrong video or audio.

Content Protection (HDCP) – an HDCP problem usually results in continuous, periodic flashing video (every 2 seconds).

Physical Layer problems (TMDS)

Intra-Pair Skew – problem results in pixel sparkles or video cutting out.

Other physical layer impairments (skin effect, dielectric loss) – problem results in pixel sparkles or video cutting out.

Problem Types Addressed in this Training Class

Physical Layer problems (DDC)

Physical layer impairments (skin effect, dielectric loss) – problem results in incorrect video (if it causes and EDID problem) or periodic flashing video if the content is protected with HDCP.

HDMI Anatomy

HDMI Anatomy (v1.4)

HDMI

Transmitter HDMI

Receiver

Display Data Channel (DDC) HDCP

CEC

HDCP &

EDID

TMDS Channel 0 (R V/H sync)

CEC

HEAC

(HEC/ARC)

HEAC

(HEC/ARC)

TMDS Channel 1 (G Control)

TMDS Channel 2 (B Control)

TMDS Clock Channel

HDMI Source HDMI Sink

CEC Bus

Utility Line/+5V

Detect High / Low Hot Plug Detect Line

Video

Audio

Control/Status

Video

Audio

Control/Status

Active Video

Data island packets

occur in the vertical

and horizontal

blanking

HDMI Data Islands Related Packets

HSYNC

V

S

Y

N

C

Vertical Sync

Delay(Lines)

Horizontal Sync Delay (Pixels)

Vertical Sync

Pulse Width

(Lines)

Vertical

Blanking

Vertical Res

Active

Lines

Vertical

Total Lines

Horizontal Blanking

Horizontal Resolution - Active (Pixels)

Horizontal

Rate – Rate

each line

Is rendered

Data Islands

Audio Sample Packets

Audio Clock Regeneration

Audio Channel Status

1

2

3

29

30

31

32

33

34

35

36

748

749

750

HDMI Connection Sequence

A - 5v from

source

B – Hot plug

assert from

sink

C - Read Sink’s

EDID

E - Begin HDCP

authentication

F - Completion

of HDCP

authentication

A

B

C

| | | | | E | | | | | F

5V

Hot Plug

AN

BCAPS

AKSV

BKSV

5V

Hot Plug

EDID EDID

STB AVR

TV

1st part of HDCP

authentication

(upstream)

Upstream Downstream

Ro

Ri

Unencrypted Video

Common Solutions for HDMI Problems

Swapping components. Resolving an HDMI problem usually requires replacing a component, device or cable; sometimes adding a device can resolve a problem.

Make sure the source and the sink device have common supported resolutions and audio formats.

Turn down the system and repower from sink to source.

Make sure that both the source and sink device are HDCP compliant.

Swap ports on distribution devices.

Use active rather than passive extenders, active extenders provide a more reliable signal.

Reseating a cable.

HDMI 2.0 – Backward Compatible with HDMI 1.x

4K@50/60, (2160p), which is 4 times the resolution of 1080p/60 video resolution.

Support for the wide angle theatrical 21:9 video aspect ratio.

Up to 32 audio channels for a multi-dimensional immersive audio experience.

Up to 1536kHz audio sample frequency for the highest audio fidelity.

Simultaneous delivery of dual video streams to multiple users on the same screen.

Simultaneous delivery of multi-stream audio to multiple users (up to 4).

Dynamic synchronization of video and audio streams.

CEC extensions provides expanded command and control of consumer electronics devices through a single control point.

Quantum Data 780 HDMI Test Instrument

Quantum Data 780 Test Instrument

HDMI Tx

Reference Source

HDMI Rx

Reference Sink

Touch Screen operation

View incoming video

Digital audio outputs:

SPDIF & TOSLink

Component

analog output

4 HDMI Passive

Monitoring ports

780 Test Instrument Developed For the Industry

780 Test Instrument developed in response to request from HDMI, LLC and CEDIA.

HDMI Troubleshooting course developed by Quantum Data centered around the 780 Test Instrument.

Quantum Data delivered the HDMI Troubleshooting class the first few times and then transitioned to CEDIA.

780 Benefits

Pre-screen and verify interoperability of new HDMI components, devices and entire networks in the lab prior to deployment.

Pre-screen and verify existing HDMI components in a client’s home.

Reduce time on-site by isolating interoperability problems to the faulty component or device more quickly.

Reduce the likelihood of callbacks by pre-emptively identifying issues that may arise over time.

Convey professionalism and expert-level knowledge.

Quantum Data remote support and consulting for free.

Troubleshooting Principles and Methods

Troubleshooting Principles

Avoid the need to troubleshoot by prequalifying existing equipment in the residence (customer) and prequalify equipment that you procure in your lab prior to the installation.

Determine if HDMI system has ever worked. If so what changed? Take careful notes.

Make one Change at a time to limit the variables to only one.

Simplify the HDMI system to the most simple configuration that still exhibits the symptom.

Substitute suspect devices or components with known-good source/sink devices or test equipment.

Disable Protocols – Disable CEC and HDCP if possible. Disabling HDCP will immediately tell you if the problem is related to HDCP.

Use the diagnostic procedures which provide the greatest insight, target the most likely causes and are easiest to conduct.

780 Troubleshooting Test Methods

Substitution with emulation and segmentation. Emulates both sources and sinks.

Diagnostic tests for both HDMI sources and sinks.

Passive monitoring of HDCP transactions and CEC messages between HDMI devices in an existing network.

Loop test with pseudo-random noise pattern for running pixel error tests on HDMI cables and distribution networks.

HDMI Sink Tests – 780 Emulating an HDMI Source

Source

e.g. STB

Repeater

e.g. A/V receiver

Switch

e.g. matrix switch

Extender

e.g. Cat5/6

Sink

e.g. HDTV

780 HDMI Source Tests – Emulating an HDMI Sink

Source

e.g. STB

Repeater

e.g. A/V receiver

Switch

e.g. matrix switch

Extender

e.g. Cat5/6

Sink

e.g. HDTV

Passively monitor DDC transactions and connection events (hot plug and 5V) between devices in HDMI system.

Passive monitoring enables you to identify the root cause of HDMI handshake problems.

780 Test Method - Passive Monitor of DDC Channel

Source

e.g. STB

Repeater

e.g. A/V receiver

Sink

e.g. HDTV

780 Test Instrument

780 Test Method - Passive Monitor of DDC Channel

Passively monitor DDC transactions and connection events (hot plug and 5V) between devices in HDMI system.

Passive monitoring enables you to identify the root cause of HDMI handshake problems.

Source

e.g. STB

Repeater

e.g. Switch

Sink

e.g. Extender 780 Test Instrument

780 Loop Test – Cable & Distribution Networks

Loop around cable or distribution device and run pseudo random noise pattern test.

Switch

e.g. matrix switch

Extender

e.g. Cat5/6

780 Test Instrument

Common Interoperability Problem Types

Connection Sequence

Connection Sequence Problems

Connection sequence—protocol sequence of events between a source and sink (handshaking) upon turn-up or connection—involves the following functions:

Connection detection (Hot Plug) – a hot plug problem usually results in no video & audio.

Plug and Play (EDID) – an EDID problem usually results in wrong video or audio.

Content Protection (HDCP) – an HDCP problem usually results in continuous, periodic flashing video (every 2 seconds).

No Video/Audio – Hot Plug Related Problems

Hot Plug Problem – What is the Symptom?

When there is a hot plug problem, you will get no video and no audio.

Note: There are other problems which can cause a no video condition (VESA formats [vertical frame rates] are

imprecise, EDID corrupt, old HDCP source)

Hot Plug (Connection Detection) – What is it?

Hot plug is a signal to an HDMI source indicating that an HDMI sink is connected.

HDMI source provides +5V to the sink which the sink uses to generate the hot plug assertion voltage.

A repeater passes a hot plug pulse (100ms) to an upstream HDMI source device.

+5V Pin 18

Hot Plug Pin 19

Source

e.g. STB

Sink

e.g. HDTV

AVS Forum Issues – Hot Plug Related Problem

Symptom: No picture following standby

“Having problem with media server and HDTV. Once the TV goes to

standby, the media server and HDTV will not communicate properly

and I get no video.

Probable cause: Media server not detecting hot plug; media server

not sending proper +5V; HDTV not asserting hot plug.

Diagnostics: Swap Media server with 780, check hot plug. Swap

HDTV with 780. Passive monitor to read +5V.

Resolution: Swap cable, replace media server or put “fix it” device

between media server and HDTV.

Diagnose No Video/Audio Problem with 780

Use 780 to emulate a known good source and run diagnostic tests downstream toward sink starting from source.

First verify that you have a good cable or swap existing cable with a known good cable.

Verify that you can get a basic picture at any resolution on the sink (e.g. HDTV). Try 480p at 8 bits and RGB color space.

Note: There is no way that sending an unsupported audio format can result in no picture. But sending an unsupported video format can result in no audio (and of course no video).

Start tests from source; then repeat tests at each segmentation point toward the downstream.

Replace the sink device with 780. Use 780 to emulate a known-good sink to check for picture.

Diagnose No Video/Audio Problem – Emulate Source 780 emulates known-good source: Select 480p60 format, 8 bit, RGB. Select any standard image (SMPTEBar). Check pattern on display. Repeat for other formats. Move 780 downstream toward sink to

segment.

Diagnose No Video/Audio Problem – Segmentation 780 emulates known-good source: Select 480p60 format, 8 bit, RGB. Select standard image (SMPTEBar). Use any pattern - check pattern on display. Repeat for other formats. Move 780 downstream toward sink to

segment and repeat tests.

Diagnose No Video/Audio Problem – Emulate Source 780 emulates known-good source: Run HDCP test to check for hot plug

error notification.

Diagnose No Video/Audio Problem – Emulate EDID 780 emulates known-good sink: Use EDID with capability for all formats. Use EDID of HDTV in system. Check for image on 780 display. Move 780 downstream toward source to

segment.

Diagnose No Video/Audio Problem – Emulate Sink 780 emulates known-good sink: Use EDID with capability for all formats. Use EDID of HDTV in system. Check for image on 780 display. Move 780 toward source to segment.

Diagnose No Video/Audio Problem – Emulate a Sink 780 emulates known-good sink: Use EDID with capability for all formats. Use EDID of HDTV in system. Check for image on 780 display. Move 780 toward source to segment

and repeat test.

Improper Video / Audio – EDID Problems

EDID Problem – What is the Symptom?

When there is an EDID problem, there is usually video and audio but it is not optimal

and not what is expected.

Note: In some cases, a no video condition can result. Why? Could have video without audio.

Extended Display Identification Data (EDID)

What is the purpose of an EDID?

EDID is an HDMI sink’s way of describing its capabilities to an HDMI source device.

The HDMI source selects its video and audio output in accordance with what HDMI sink device supports.

Note: An EDID cannot be changed in a TV except through a firmware update.

EDID – What is it? How does it work?

Source reads sink’s EDID (e.g. HDTV) when connected.

Source reads EDID and checks for the capabilities of the sink.

Source outputs the best audio and video it is capable of transmitting that is consistent with the capabilities expressed in the EDID of the display and in accordance with the content.

Read EDID DDC Data Pin 16

Reply EDID DDC Gnd Pin 17

Source

e.g. STB

Sink

e.g. HDTV

EDID – What is it? How does it work?

AV Receiver

EDID (DDC)

AV Receiver’s

Sink

Source Device

2 – AV receiver

incorporates its audio

data into the EDID and

modifies (may reduce) the

video timings it forwards

to the source device.

3 – AV receiver asserts

hot-plug and the

source reads video

and audio capabilities

from EDID of AV

receiver’s sink side.

4 – Source device

outputs video and

audio based on the

capabilities of the EDID

passed by the AVR .

DTV EDID (DDC)

AV Receiver’s

Source

1 – Display device

asserts hot-plug and

AV receiver’s source

side reads video and

audio capabilities from

EDID of display.

AVS Forum Issues – EDID Related Problems

Symptom: Not getting HD on my Plasma

STB–-HDMI AVR HDTV = SD video; stereo audio

STB–-HDMI HDTV = HD video

“When I go through my A/V receiver I do not get full HD video on the Plasma and I do not get Dolby Digital Plus on my receiver. If I go around the A/V receiver I do get HD video.”

Probable Causes: A/V Receiver is mishandling EDID from downstream HDTV. Therefore source sends out minimal video and audio.

Diagnostics: Check EDID on sink side of A/V receiver; Check EDID on source side of A/V receiver. Emulate known-good EDID at DVD output; Emulate known-bad EDID at DVD output.

Resolution: Short term, use SPDIF to A/V receiver. Long term, replace A/V receiver or update F/W.

AVS Forum Issues – EDID Related Problem

Symptom: No audio with projector

DVR –-HDMI A/V receiver —HDMI Projector = No audio

“DVR connected to A/V receiver to Projector, all HDMI connections.

No audio with projector plugged into receiver.”

Probable cause: A/V receiver not substituting its audio block into

EDID from projector.

Diagnostics: Check EDID on source side of projector; Check EDID

on source side of A/V receiver. Emulate known-good EDID on sink

side of A/V receiver; Emulate projector EDID on sink side of

projector.

Resolution: Short term: Bypass A/V receiver; long term: replace

A/V receiver.

Diagnose Incorrect Video/Audio Problem with 780

Use 780 to emulate a known good source and run sink diagnostic tests. Verify that you have a good cable or swap existing cable with a

known good cable.

Run an EDID test on the sink.

Checks for proper structure and checksum errors. Verify video and audio capabilities. Note: Sometimes audio formats, channels, sampling rates are not supported by low resolution video formats.

Start tests from source; repeat tests at each segmentation point working downstream.


Use 780 to emulate a known good sink and emulate sink’s EDID; run diagnostic tests starting from sink.

Run a video display test.

Run a video analysis test.

Run an audio analysis test.

Run frame compare test.

Verify video and audio capabilities.

Note: Sometimes audio formats, channel count and sampling rate configurations are not supported by low resolution video formats.

Start tests from sink; repeat tests at each segmentation point working upstream.


Replace both source and sink with 780 and check EDID handling of an HDMI distribution system.

Run a cable or repeater test.

Diagnose Incorrect Video Problem at Family Room

Cable STB

4x4 HDMI Switch

Satellite STB

Media PC

HDMI Cat6

Extenders (3)

DVD

DVD

DVD

AVR

HDTV

HDTV

HD Projetor

Game

System

Family

Room

Home

Theatre

Bedroom

Basement – Equipment Room

Cable STB

4x4 HDMI Switch

HDTV

Family Room Basement – Equipment Room

Cat Extender

Diagnose Incorrect Video Problem (a)

Video Analysis &

EDID Source Test

Test: Video Analysis Test & Source EDID Test

Objective: Determine if STB can read the HDTV’s EDID and is sending

the proper video timing, colorimetry data and infoframes when directly

connected.

Pass: If the STB passes, run a similar test on the downstream side of

the matrix switch. (Next slide.)

Fail: If the STB fails then substitute the test instrument for the STB and

run a Video Pattern test. If this also fails you have confirmed that there

is a problem with the STB and you should swap it out or get a firmware

upgrade.

EDID Read

Diagnose Incorrect Video Problem (b)

Test: Video Analysis & EDID Source Tests

Objective: Determine if matrix switch enables the STB to

read HDTV’s EDID and pass proper video timing, colorimetry

settings and infoframes.

Pass: If this test passes, run a similar test on the downstream

side of the extender. (Next slide.)

Fail: If this test fails then run a Video Pattern and Video

Analysis test on the switch to verify that it is the problem

component. If you see problems here this confirms that the

matrix switch is the problem component and you should swap

it out.

Video Analysis &

EDID Source Test Cable STB

4x4 HDMI Switch

HDTV


Cat Extender

Cable STB

4x4 HDMI Switch

HDTV


Cat Extender

Diagnose Incorrect Video Problem (c)

Test: Video Analysis & EDID Source Tests

Objective: Determine if extender enables the STB to read the

HDTV’s EDID and pass proper video timing, colorimetry settings

and infoframes.

Pass: If this test passes, run a Video Pattern test on the HDTV.

(Next slide.)

Fail: If this test fails then run a Video Pattern and Video Analysis

test simultaneously on the extender to confirm that it is the

problem device. If you see problems here this confirms that the

extender is the problem component and you should swap it out.

Video Analysis &

EDID Source Verify

Cable STB

4x4 HDMI Switch

HDTV


Cat Extender

Diagnose Incorrect Video Problem (d)

Test: Video Pattern

Objective: Determine if the HDTV can render an image

using a variety of video formats and colorimetry settings

from a known-good source.

Pass: If this test passes then the most likely cause is

that the Cable STB and HDTV are not exchanging EDID

and/or infoframe data in all cases. You might consider

swapping the STB out.

Fail: If this test fails then you may consider swapping

the HDTV for a more modern model.

Video Pattern

Diagnose Incorrect Audio Problem in Home Theatre

Cable STB

4x4 HDMI Switch

Satellite STB

Media PC

HDMI Cat6

Extenders (3)

DVD

DVD

DVD

AVR

HDTV

HDTV

HD Projetor

Game

System

Family

Room

Home

Theatre

Bedroom


DVD

AVR

HD Projector Home Theatre Room

Diagnose Incorrect Audio Problem (a)

Audio Analysis &

EDID source

Test: Audio Analysis & EDID Source Tests

Objective: Determine if the DVD player will play multi-channel

compressed audio. Run this test both with the A/V receiver’s

EDID and a known-good A/V receiver EDID.

Pass: If the DVD player can play out multi-channel

compressed audio properly to the test instrument with the A/V

receiver’s EDID and a known-good A/V receiver EDID then run

an audio pattern test through the A/V receiver. (Next slide.)

Fail: If the DVD player does not play out multi-channel

compressed audio, then check the DVD player’s spec sheets

and the content on the disk. May need to replace

the DVD player.

DVD

AVR


Diagnose Incorrect Audio Problem (b)

Test: Audio Pattern Test

Objective: Determine if the A/V receiver can play out multi-channel

compressed audio (e.g. Dolby Digital Plus).

Pass: If the A/V receiver can play out multi-channel compressed

audio, then run an EDID verification test to check to see what EDID

the A/V receiver is passing upstream to the source. (Next slide.)

Fail: If the A/V Receiver cannot play out the proper audio then this

means that the A/V receiver is either not configured properly or

does not support that particular audio format. May have to swap out

the A/V receiver for a newer model.

Audio Pattern

DVD

AVR


Diagnose Incorrect Audio Problem (c)

Test: EDID Sink Verification

Objective: Determine if the EDID passed upstream by the A/V receiver

is valid and correct (i.e. has the correct audio block).

Pass: If the A/V receiver does pass the correct audio block in the EDID

upstream, then the projector is a suspect component. It may not be

transmitting the EDID over the DDC properly. Run an EDID source test

on the downstream side of the A/V receiver. (Next slide.)

Fail: If the A/V receiver is not passing the proper audio in the EDID, then

this means that the A/V receiver is not forwarding EDID information

properly. The workaround is to bypass the A/V receiver and connect the

HDMI directly to the projector and connect a SPDIF cable to the A/V

receiver for audio.

EDID Sink Test

DVD

AVR


Diagnose Incorrect Audio Problem (d)

EDID Source Test

Test: EDID Source Test

Objective: Determine if the DVD will play out multi-channel compressed audio to an

EDID of a known good sink passed through the A/V receiver. Run this test both with the

HDTV’s (projector’s) EDID and using an EDID from a known-good sink.

Pass: If the DVD player plays out the multi-channel compressed audio properly through

the A/V receiver this means that HDTV (projector) is the suspect component. Its EDID

may be getting corrupted or may not be able to be parsed by the A/V receiver. One

workaround would be to try and use a different HDMI port on the projector. Another

solution is to bypass the A/V receiver and connect the HDMI directly to the projector and

connect a SPDIF cable to the A/V receiver for audio.

Fail: If the DVD player does not play out multi-channel compressed audio, then the A/V

receiver is the suspect device. You should check its configuration and specification.

780 emulates source: Read EDID at 780 Tx port. Check for errors. Verify video resolution and content. Initiate hot plug and repeat.

Diagnose Incorrect Video Problem with 780

780 emulates source: Move 780 downstream toward sink to

segment. Read EDID at 780 Tx port. Check for errors. Verify video resolution and content.


Diagnose Incorrect Video Problem with 780 780 emulates source:

Connect to HDMI sink and read EDID. Use EDID on 780 Rx port. Initiate hot plug. Run Audio/Video analysis tests. Repeat to emulate other test EDIDs.

Diagnose Incorrect Video Problem with 780 780 emulates EDID of sink:

Connect to HDMI sink and read EDID. Copy to 780 Rx port. Initiate hot plug. Run video analysis tests. Repeat to emulate other test EDIDs.

780 emulates both source and sink: Emulate known-good EDID at 780 Rx port. Read EDID on 780 Tx port. Check for errors. Verify video content.


780 emulates both source and sink: View/verify video. Send various resolutions from 780

HDMI Tx and Read AVI and timing. Verify video content and resolution. Verify A/V parameters.


780 emulates source: Read EDID at 780 Tx port with sink. Check for errors. Verify audio content. Repeat for other audio formats.

Diagnose Incorrect Audio Problem with 780

780 emulates source: Read EDID at 780 Tx port without sink. Check for errors. Verify audio content. Repeat for other audio formats.


780 emulates source: Read EDID. Check for errors. Send various audio formats supported

in the A/V receiver’s EDID. Verify audio content.


780 emulates source: Read EDID. Check for errors. Send various audio formats supported

in the A/V receiver’s EDID with sink. Verify audio content.


780 emulates source: Move 780 downstream toward audio

rendering device (AVR) to segment. Send various audio formats supported

in the A/V receiver’s EDID without sink. Verify the audio content.


780 emulates both source and sink: Send various audio formats supported

in the A/V receiver’s EDID. Verify audio metadata. Initiate hot plug and repeat.


780 emulates both source and sink: Send various audio formats supported

in the A/V receiver’s EDID without sink. Verify audio metadata. Initiate hot plug and repeat.


Quantum Data EDID Library – Free Test EDIDs

Quantum Data has created a freely accessible EDID library.

Variety of Commercial EDIDs from HDTVs.

Sample EDIDs created from Quantum Data EDID utilities. A variety of capabilities.

Test EDIDs that are known-bad.

www.quantumdata.com/edid/

Naming convention: - Interface type, e.g. “H” for HDMI; “D” for DVI - Preferred timing “8” for 1080; “7” for 720, “4” for 480 - Scan, e.g. “P” for Progressive - Highest audio, e.g. “H” for TrueHD; “L” for LPCM; “D” for DolbyD - 2 Sequence numbers to avoid name space collisions - Type of EDID, e.g. “C” commercial, “T” for test, “X” for bad EDIDs

http://www.quantumdata.com/edid/

Flashing Video – HDCP Problems

HDCP Problem – What is the Symptom?

When there is an HDCP problem, typically there is continuous, periodic flashing video

(about every 2 seconds).

Note: With an HDCP failure you will never have audio without video. In some cases, a no video condition can result. Why?

HDCP Interoperability

High Definition Content Protection

“HDCP is the hardest thing about HDMI (or any digital interface) interoperability”. Why?

The goals of HDMI compliance and HDCP compliance are different.

Many devices were shipped without any HDCP testing until 2006

Cable, Satellite, and IPTV service providers update the

software in their set-top-boxes often without warning.

AVS Forum Issues

Symptom: “Annoying HDMI blinking!”

STB HDMI AVR HDMI HDTV = Video/Audio blinking

STB HDMI ===========> HDTV = OK

DVD HDMI AVR HDMI HDTV = OK

“I get blinking/dropout of audio/video. Tried updating the TV's firmware. When I watch

from a DVD recorder (HDMI) going thru the same receiver, I don’t see the blinking occur.

Now bypassing the AV receiver for cable viewing, but obviously this isn't what I want to

do forever. It could be the ports for the SAT STB on the AV receiver.

I believe the problem is with the STB or the cable service. And possibly something with

the AV receiver in the middle. But since it can serve up content from my HDMI DVD

player fine, I doubt the receiver is completely to blame.”

Probable cause: HDCP Authentication failure. STB does not support repeaters or does

not parse HDCP repeater bit.

Diagnostics: Swap DVR with 780, disable HDCP. Passively monitor DDC transactions

at the STB, AV receiver and HDTV.

Resolution: Swap out STB.

A - HDMI source (e.g. DVD player) outputs +5V power toward HDMI sink (e.g. HDTV).

B - Source waits for hot plug detect to be asserted (i.e. to go to its high voltage state).

C - Source reads the sink’s capabilities in the sink’s EDID.

D - Source chooses video and audio formats and outputs unencrypted video and audio content & metadata.

E - Source performs HDCP authentication if content is flagged as content protected.

F - Source monitors connection every 2-seconds with an HDCP heartbeat (Ri).

Source re-authenticates if there is a mismatch in the heartbeat (Ri’) value or if a hot plug event occurs.

Sink uses metadata to get the picture and sound correct.


A

B

C

D | | | | | | E | | | | | | F

5V

Hot Plug

AN

BCAPS

AKSV

BKSV

5V

Hot Plug

EDID EDID

STB AVR

TV

1st part of HDCP

authentication

(upstream)

Upstream Downstream

Ro

Ri

Unencrypted Video


A - 5v from

source

B – Hot plug

assert from

sink

C - Read Sink’s

EDID

E - Begin HDCP

authentication

F - Completion

of HDCP

authentication

A

B

C

| | | | | E | | | | | F

5V

Hot Plug

AN

BCAPS

AKSV

BKSV

5V

Hot Plug

EDID EDID

STB AVR

TV

1st part of HDCP

authentication

(upstream)

Upstream Downstream

Ro

Ri

Unencrypted Video

Diagnosing HDCP Problems with the 780

Run sink HDCP test starting from source.

Run source HDCP test starting from sink.

Monitor HDCP transactions.

Run passive monitoring test around suspect devices.

Diagnose Flashing Video on TV Family Room from STB

Cable STB

4x4 HDMI Switch

Satellite STB

Media PC

HDMI Cat6

Extenders (3)

DVD

DVD

DVD

AVR

HDTV

HDTV

HD Projetor

Game

System

Family

Room

Home

Theatre

Bedroom


Cable STB

4x4 HDMI Switch

HDTV

Family

Room


Cat Extender

Diagnose Flashing Video on TV Family Room from STB (a)

Test: HDCP Sink Test

Objective: Determine if you can authenticate HDCP from a known-good source

through the HDMI network. First enable HDCP then disable HDCP.

Fail: If you get video with HDCP disabled but still see flashing when HDCP is

enabled, this means that the problem is HDCP related but the STB is not the likely

suspect device. Continue testing downstream (next slide).

Pass: If you do get video in either case (HDCP enabled or disabled), then the most

likely cause is the STBs HDCP authentication protocol. Confirm by running source

test with test equipment on suspect STB. Resolution is to swap the STB.

Sink HDCP Test

Cable STB

4x4 HDMI Switch

HDTV

Family

Room


Cat Extender

Diagnose Flashing Video on TV Family Room from STB (b)


Objective: Determine if you can authenticate HDCP from a known-good source through the

HDMI network. First enable HDCP then disable HDCP.

Fail: If you get video with HDCP disabled but still see flashing when HDCP is enabled, this means

that the problem is HDCP related but the HDMI switch is not the likely suspect device. Continue

testing downstream (next slide).

Pass: If you do get video in either case (HDCP enabled or disabled), then the most likely cause is

that the STB is incapable of HDCP authentication through the HDMI switch. Confirm by running

source test with test equipment on suspect HDMI switch. Resolution is to swap the HDMI switch.

Sink HDCP Test

Cable STB

4x4 HDMI Switch

HDTV

Family

Room


Cat Extender

Diagnose Flashing Video on TV Family Room from STB (c)


Objective: Determine if you can authenticate HDCP from a known-good source through the HDMI

network. First enable HDCP then disable HDCP.

Fail: If you get video with HDCP disabled but still see flashing when HDCP is enabled, this means that

the problem is HDCP related but the extender is not the likely suspect device. The root cause may be a

physical layer problem on the DDC; corrupt bits. Resolution is to replace it.

Pass: If you do get video in either case (HDCP enabled or disabled), then the most likely cause is that

the STB is incapable of HDCP authentication through the HDMI switch and extender. Confirm by running

source test with test equipment on suspect HDMI switch. Resolution is to swap the extender.

Sink HDCP Test

Cable STB

4x4 HDMI Switch

HDTV

Family

Room


Cat Extender

Diagnose Flashing Video on TV Family Room from STB (d)

Test: Source Test to confirm

Objective: Verify that the HDCP problem occurs with a

known-good sink device.

Source Test Source Test Source Test

780 emulates source: Run HDCP Test downstream. Disable then Enable HDCP Check for hot plug detect error Check for HDCP errors Initiate hot plug and repeat

Diagnose Flashing Video Problem with 780

780 emulates source: Move 780 downstream toward sink to

segment. Test HDCP. Check for errors. Verify video/audio content.


Connect test equipment to network: Monitor DDC traces passively. Initiate connection event. Check for 5 volts and hot plug. Check for EDID read. Check for HDCP authentication errors.


Diagnose Flashing Video Problem with 780 Connect test equipment to source:

Run Source HDCP test. Verify HDCP authentication Check number of keys.

Diagnose Flashing Video Problem with 780 Connect test equipment to source:

Move 780 upstream toward sink to segment.

Run Source HDCP test. Verify HDCP authentication Check number of keys.

Physical Layer Problems

Physical Layer Problem – What is the Symptom?

When there is a physical layer problem related to the TMDS link,

there is either no video or a degraded video; sparkles or excessive noise.

When there is a physical layer problem related to the DDC channel, the symptoms

may cause HDCP or EDID problems but they are typically intermittent not constant.

Pixel Errors (“Sparkles”)

What causes pixel errors (“sparkles”)?

Intra-pair skew – The loss within one of the TMDS pairs. Typically results for differential lengths of the twisted pair. Closes horizontal axis of the eye diagram.

Physical impairments – Distortion or “smear” of the signal due to attenuation of high frequencies. Skin effect and dielectric loss. Closes vertical axis of the eye diagram.

Diagnosing physical layer problems requires very expensive equipment such as high speed oscilloscopes.

Therefore diagnostics of physical layer problems in the field is accomplished by inference and general symptom, i.e. pixel errors (“sparkles”) or intermittent snow or loss of video due to “cliff effect.”

Inter-Pair Skew Cause of Velocity/Length Error

Intra-pair skew

caused by

asymmetric

twists, which in

this case makes

the red wire longer

Intra-Pair Skew – Real Cable

One Digital Pair

… but we live in

the real world

where wires

aren’t perfect

To keep the eye

open, limit wire

cable length to

≈10 standing bits

Note: active

wires exist that

can correct

skew.

HDMI Cable – A Low Pass Filter

Cables pass low frequency components of a signal.

Attenuate high frequency components of a signal.

Frequency

HDMI channel characteristics

Low High

Digital Signal Transmission

1st harmonic

HDMI Square Wave

3rd harmonic

9th harmonic

Sampling points

Threshold

voltage

HDMI Equalization & Pre-emphasis

HDMI uses Equalization and Pre-Emphasis to correct for signal distortion on long signal transmissions.

What is Equalization? The process of adjusting the strength of certain frequencies

(typically high frequencies in HDMI) within a received signal.

volta

ge

Frequency

HDMI channel characteristics HDMI equalization filter HDMI channel w/ Equalization

0

1

Low High Frequency Low High Frequency Low High

HDMI Equalization & Pre-emphasis

Equalization increases the signal strength of the high frequencies over long distances but also increases the noise.

The signal-to-noise level is not improved.

What is Pre-emphasis? HDMI 1.2 prohibited pre-emphasis because of restrictions on

overshoot. HDMI 1.3 removed these restrictions.

The process designed to increase the magnitude of some higher frequencies with respect to the magnitude of lower frequencies in order to improve the overall signal-to-noise ratio.

Pre-emphasis increases the amplitude for a specific amount of time.

Diagnosing Physical Layer Problems with the 780

Run Cable test on suspect cables.

Run Repeater test on suspect distribution devices.

Run video tests at high speeds and deep color.

Diagnose Sparkles in Family Room from STBs

Cable STB

4x4 HDMI Switch

Satellite STB

Media PC

HDMI Cat6

Extenders (3)

DVD

DVD

DVD

AVR

HDTV

HDTV

HD Projetor

Game

System

Family

Room

Home

Theatre

Bedroom


Cable STB

4x4 HDMI Switch

HDTV


Cat Extender

Diagnose Sparkles in Family Room from STBs (a)

Test: Cable/Repeater Test

Objective: Determine if the HDMI cables to and from the

matrix switch and the switch itself are passing good video.

Pass: If this test passes then the most likely cause is the

Extender. Run a test on the Cat extender. (Next slide.)

Fail: If this test fails then you should perform individual

cable tests on each cable. If one fails, replace it. If they do

not fail, replace the matrix switch.

Cable/Repeater Link Test

Cable STB

4x4 HDMI Switch

HDTV


Cat Extender

Diagnose Sparkles in Family Room from STBs (b)

Test: Cable/Repeater Test or Frame Test

Objective: Determine if the HDMI cables to and from the matrix switch,

the switch itself and the extender are passing good video. If you cannot

run the cable/repeater test, then run the frame compare test.

Pass: If this test passes run a cable test on the HDMI cable to the

HDTV. (Next slide.)

Fail: If this test fails then the most likely cause is the Extender or the Cat

cable. Try running a new Cat 5 cable temporarily and repeat this test.

Frame Compare

Cable STB

4x4 HDMI Switch

HDTV


Cat Extender

Diagnose Sparkles in Family Room from STBs (c)

Test: Cable/Repeater Test

Objective: Determine if the HDMI cables to and from the

matrix switch and the switch itself are passing good video.

Pass: If this test passes then the most likely cause is that the

extender is exhibiting intermittent errors. Replace/swap the

extender.

Fail: If this test fails then you should replace the cable.

Cable Link Test

Connect test equipment to HDMI cable or network: Run Repeater Test. Check for errors. Initiate hot plug and repeat.


Connect test equipment to HDMI cable as shown Run Video test with high speed

resolutions and deep color. Use dark test pattern. Check for errors.


Use 780 to emulate sink. Run Frame Compare test. Check for errors.

Procedure – Run Far End Frame Compare Test

Miscellaneous

AVS Forum Issues Symptom: No Video/Audio with A/V Receiver

Hi EveryBodies.

After intensive search on the net I found this Forum and I am sure You will answer my issue (I hope )

So here is my devices list:

BluRay player (Samsung), Satellite Decoder, AV receiver, (Yamaha 665) and HDTV (LG LH7020).

All were connected using HDMI cable (1.3). It was working fine during at least one year since ...

about one month.

BR Player ==> AV receiver ==> TV LG (KO)

Sat Dec ==> AV receiver ==> TV LG (KO)

BR Player ===============> TV LG (OK)

Sat Dec ===============> TV LG (OK)

BR Player ==> AV receiver ==> Another HDTV (OK) (not LG) for check

When I write KO it means no pictures, the sound during few secondes then no sound, then sound

during few secondes.... The red logo "HDMI" on the AV receiver is also flashing (same as sound). One

time I get a noisy "red" screen during few secondes.

I bring the AV Receiver to the customer support and they did not find any problem.

Now I just want to know what is the wrong device. What should I changed ?

AVS Forum Issues – EDID Related Problems Symptom: Pink tint on TV

STB –-HDMI HDTV = Pink tint on TV

“HDMI communication problem. Sometimes the picture has a pink tint…

I can resolve this issue if I connect using component instead of HDMI. I can also resolve the issue if I connect to a different brand of television.

I have replaced HDMI cable, swapped television for same new one, and replaced DVR box for same new. Satellite provider has been out to see the issue and does not have a resolution. I have spoken with HDTV manufacturer and they want me to send pictures to them, which I will do.”

Possible Causes: Mismatch in color space. Source sending YCbCr to an HDTV in RGB mode. (1) EDID or (2) AVI Infoframe.

Diagnostic: Swap TV with TE and read AVI infoframe coming from STB. Read EDID from TV verify it supports YCbCr.

Resolution: Source STB not reading EDID properly or sending incorrect infoframe; consider replacing STB source.

AVS Forum Issues Symptom: Audio Dropout

STB –-HDMI--> AVR —HDMI HDTV = Audio drops out

STB –-HDMI--> HDTV

STB –-optical--> AVR

“Watching the ballgame last night and suddenly no sound. I noticed only

analog picking up on AV receiver, no matter what mode I had it on. I have

changed the HDMI cable and still only analog shows up. Does this sound

like the AV receiver is the problem? I have had the HDMI hooked up for

over a year now. Does anyone have any ideas?”

Possible causes:

(1) Audio buffer being overrun by audio sample packets.

(2) Audio infoframes missing.

(3) Using PC (VESA) formats with not enough blanking

Resolution: Swap out STB (source).

HDMI Anatomy (v1.4)

HDMI

Transmitter HDMI

Receiver

Display Data Channel (DDC) HDCP

CEC

HDCP &

EDID

TMDS Channel 0 (R V/H sync)

CEC

HEAC

(HEC/ARC)

HEAC

(HEC/ARC)

TMDS Channel 1 (G Control)

TMDS Channel 2 (B Control)

TMDS Clock Channel

HDMI Source HDMI Sink

CEC Bus

Utility Line/+5V

Detect High / Low Hot Plug Detect Line

Video

Audio

Control/Status

Video

Audio

Control/Status

Active Video

Data island packets

occur in the vertical

and horizontal

blanking

HDMI Data Islands Related Packets

HSYNC

V

S

Y

N

C

Vertical Sync

Delay(Lines)

Horizontal Sync Delay (Pixels)

Vertical Sync

Pulse Width

(Lines)

Vertical

Blanking

Vertical Res

Active

Lines

Vertical

Total Lines

Horizontal Blanking

Horizontal Resolution - Active (Pixels)

Horizontal

Rate – Rate

each line

Is rendered

Data Islands

Audio Sample Packets

Audio Clock Regeneration

Audio Channel Status

1

2

3

29

30

31

32

33

34

35

36

748

749

750

Test Questions True or False

1. True or False Infoframes are sent from an HDMI source to an HDMI sink device?

2. True or False. In an HDMI connection sequence the EDID is always read after HDCP authentication?

3. True or False. HDCP transactions for content protection occur in the HDMI video blanking?

4. True or False. The EDID is read over the CEC bus?

5. True or False. Category 1 cables have been tested up to 1080p60?

6. True or False. A Set Top Box is an example of an HDMI sink “receiver”?

7. True or False There is a separate hot plug used by repeaters to indicate a downstream connection event?

8. True or False. Pixel sparkles are a symptom of an HDCP authentication failure?

9. True or False. The HDMI infoframes are sent over the DDC channel?

10. True or False. HDCP authentication is more likely to fail when YCbCr is used instead of RGB?

11. True or False HDCP authentication is more difficult where there is an HDCP repeater used between a source and a sink device.

12. True of False When a sink device is swapped out and a reconnection event occurs, HDCP authentication should reoccur?

13. True or False Improper video resolution can be caused by an EDID interoperability problem?

Test Questions Multiple Choice

1. What two HDMI device functions does an HDMI repeater device have? A – scalar/source B – extender/sink C – source/sink. D – booster/converter

2. What is the most likely symptom of continuous HDCP authentication failures? A – continuous, periodic, flashing video. B – improper video resolution C – audio pops & clicks D – bad EDID

3. What are the circumstances under which a hot plug event occurs? A – EDID has been read B – content protection flag is set C – a sink device is connected to source. D – audio clock is regenerated

4. AVR is suppose to do what with the HDTV’s EDID? A – ignore the downstream EDID and forward its own EDID B – forward the HDTV EDID to source without modifying it C - substitute its entire EDID for an HDTVs D - replace the audio block, remove any unsupported resolutions and then forward the modified EDID to the source device.

Test Questions Multiple Choice (continued).

1. Which of the following information does an EDID have? A - optimal video resolution/audio formats supported/video resolutions supported/video type &sampling modes. B - audio formats supported/video format being sent/audio clock regeneration values/optimal video resolution C – optimal video resolution/audio formats/audio clock regeneration values/audio formats supported D – video resolutions supported/audio formats supported/audio clock regeneration values/HDCP keys

2. If there was no video on an HDTV, a likely root cause is? A – no hot plug detected; inactive port on the HDTV. B - missing vendor specific infoframe C – missing audio block in the EDID D – incorrect color space

3. What is the most likely cause of the symptom of continuous, periodic, flashing video? A – bad EDID B – missing infoframes C – wrong color space (RGB/YCbCr) D – failed HDCP authentication.

Test Questions Multiple Choice (continued).

1. What is the highest audio capabilities of a device with the following EDID? A – Dolby Digital B – Linear PCM C – DTS Master Audio D - Dolby Digital Plus

2. The following EDID most likely an EDID from what type of device? A – HDTV B – Set Top Box C – Extender D - A/V Receiver

3. What is the preferred format of the device with the following EDID? A – 1080i30 B – 1080p60 C - 720p60 D – 480p60

troubleshooting hdmi systems - quantumdata

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