• New Patreon Tier and Early Access Content available. If you would like to support AVForums, we now have a new Patreon Tier which gives you access to selected news, reviews and articles before they are available to the public. Read more.

HDMI Handshaking Anomalies

HatManSan

Standard Member
Greetings All.

I have an interesting issue. One that has wasted much of my time and mobile bandwidth allowance. I have a client with a SKY HD box and a PS3. Nothing unusual about that. Both these sources are hooked up via HDMI to a Panasonic TX-L32E5. No amp or switchers involved. The other day they contacted me to say they had no picture from Sky. On inspection they had no image from Sky or the console. Changing HDMI leads made no difference. Swapping the inputs used from 1/2 to 3/4 again made no difference. As a SCART lead was handy I connected that up using the breakout leads supplied with the TV. A standard image was displayed from the Sky box but with terrible mains hum. This was evident at any volume on the TV. No analogue leads were available for the console so no further testing was done. Both the Sky box and the console were removed and hooked up to another TV. No image was available. Clearly a finger drifted in the direction of the two sources. Now for the interesting part. A third party lent me an HD box for testing. Hooked up to the second TV all was well. Hooked up to the original TV, there was no image! Neither of three remaining inputs provided an image. However both the console and the original HD box provide a perfect image on a PC monitor, in this case an Iiyama 2473HDS. this monitor has two HDMI inputs a DVI and a VGA input. Either device plugged into either of the two HDMI inputs resulted in a image. Syncing was a bit slow but I figured that is the monitor. My question is why do I get an image on the monitor but not from either of the two TV's? The owner has since taken the TV for repair. I expect to see it back NFF! What is different about HDMI on a monitor compared to a standard consumer HD TV? The monitor is HDCP compliant.

I am sorry this thread is a tad long. HDMI Licensing were not able to help, nor have Sky and thus far neither has the Internet.

Many thanks

Matt
 
Last edited:

Joe Fernand

Distinguished Member
AVForums Sponsor
‘The monitor is HDCP compliant’ – wouldn’t be the first time that was achieved by simply disabling HDCP in the Sink (Display), makes for a very easy life for your Tech Support Desk :devil:

Joe
 

stevelup

Distinguished Member
I'd focus on the mains hum you had when connected via analogue. It's a big clue.

First thing to try is to disconnect the LNBs from the Sky box and see what happens then.

It sounds like you have a really bad earth loop somehow.
 

HatManSan

Standard Member
A lot has happened since my last visit. The client now has a three more HD boxes and a new dish and octo LNB. The same original HD remains operative only on the PC monitor. The stand in Viera TV does not work with the box. However the same TV does work fine with one of the other HD boxes. ( I tested just one other box). I have been told the Panasonic TV that was installed originally (E5) has been repaired. Apparently the HDMI switching board was dead and has been replaced. That TV has not been returned yet. However the question about HDMI on PC monitor vs TV still remains. The original Sky HD box and PS3 do not work on any TV. They are only useable on the PC monitors HDMI input.
 

HatManSan

Standard Member
OK the TV has now been returned and installed. I reinstalled the TV in exactly the same way as before. So Sky HD was plugged into HDMI 1 and the PS3 in HDMI 2. Only the PS3 worked. I swapped the HD box and the PS3 around. The console was fine in HDMI 1 but the Sky HD box did not operate in HDMI 2. After removing both connectors from the TV. I tried the Sky HD box in HDMI sockets 1 through 4. Only 3 and 4 worked! I did the same thing with the PS3. It worked in every single socket 1 though 4, as you would expect.

To recap.

HDMI 1 2 3 4

TV. X X O O
PS3. O O O O

X = no image or sound. O = normal operation

With this new evidence in mind can anyone shed any light on this issue?

Many thanks. Matt

P.s. With the HD box connected via SCART there is no longer any hum on the audio.
 

S D I

Banned
what resolution is the PS3 and Sky box set to?

Try dropping the resolution on the SKY box until all inputs work and let us know the results.
 

HatManSan

Standard Member
On returning to the site, I have carried out the suggested res' drop.

The console works at all resolutions in ANY HDMI input. The Sky HD box does not work at ANY resolution in HDMI inputs 1 and 2 but does work at ANY resolution in HDMI inputs 3 and 4.

The facts. The Sky HD box without question worked as normal in ALL inputs prior to the TV going faulty. After the TV was declared faulty the console did not work at all in any input but now works in any and all of the four inputs.

Something appears to have happened to the Sky box, or there is still some kind of handshake issue on HDMI 1 and 2 the console ignores.

Thanks:confused:
 

S D I

Banned
WOW!, this is an interesting one.
We need Joe Fernand on this one, come on man all that reading about HDMI should enable us to drill down to the exact protocol issue here.
End of the day I presume the Sky box works on every other TV in the world on all inputs bar this TV so logically the TV is at fault.
I'm sure that after a lot of HDMI analysis by better experts than me and 50 grands worth high bandwidth HDMI diagnostics there is a logical explanation but I cannot believe it will not be determined to be the TV at fault.
I would return the TV to the repairers accompanied by the Sky Box.

I'm sorry I'm no help to you and look forward to other opinions.
 

Joe Fernand

Distinguished Member
AVForums Sponsor
Do you have access to a Laptop with an HDMI or DVI socket?

If yes you can try reading the EDID from the sockets on the TV and see if anything unusual shows up - use Monitor Asset Manager from Entech Taiwan, it's a free download.

I take it you are using the same HDMI cable for your tests of both sets of sockets on the TV.

The HDMI ports on the TV are likely in pairs on sub boards behind the sockets.

Joe
 

Mario Nicholas

Active Member
The problem with digital fault finding is; Chelsea beat Man Utd, Man Utd beat Man City, Man City beat Chelsea, so illogical results caused by hidden logical reasons. So for a quick solution you need expensive metering equipment, experience and knowledge that is generally above your job needs.
So Joe's advice to test the EDID sounds the easiest place to start, I'm having a look at the download myself, nice one Joe.
But Steve's suggestion to return the TV with the Sky box to the repairer would be my advice also, as it's really there job to fix the kit, we only get paid to install it!
 
Last edited:

The latest video from AVForums

Fidelity in Motion's David Mackenzie talks about his work on disc encoding & the future of Blu-ray
Subscribe to our YouTube channel

Full fat HDMI teeshirts

Support AVForums with Patreon

Top Bottom