Samsung LE40M86BDX no sound on HDMI after a lightning

[yoritomo]

Brand: Samsung
Model LE40M86BDX / XEC
Chassis: GTU37

Hello

This TV set got a lightning damage by HDMI1 input, originally it could not display any images from any HDMI inputs, other sources are ok, then I replaced the HDMI switch IC SIL9185CTU and associate input resistors 10ohms from HDMI1.
Now i can see the image from from any HDMI ports, but no sound on any one, do you have any clue about it, i am a bit lost to follow the digital transmission of the audio signal between chips to troubleshoot.
Perhaps the SIL9125CTU HDMI decoder which would disturb ? How to be sure ?

I checked the signals between HDMI switch IC and HDMI decoder IC , they are looking good, they i assume SIL9185CTU is doing is job , i found the clock on D2_RXCLK- and D2_RXCLK+ and variable nice looking signal on D2_RX0- D2_RX0+ D2_RX1- D2_RX1+ D2_RX2- D2_RX2+


Thanks for your help.

[CapLeaker]

Re: Samsung LE40M86BDX no sound on HDMI after a lightning

You verified you got no audio on any port. So there's not much else you can do, besides changing that SIL9125CTU.

[Davi.p]

Re: Samsung LE40M86BDX no sound on HDMI after a lightning

I would check better the soldering of the replaced chip and also the status of the connector..

[yoritomo]

Re: Samsung LE40M86BDX no sound on HDMI after a lightning

hello all

I checked already and reflowed again the chip with some flux to be sure, the first thing i did, no change, the connectors contacts and joints are correct,. the proof is that i am getting every data line oscillograms as well as clock. In input and output of SIL9185CTU, i suspect a damaged data input in SIL9185CTU too, but how come i would get a correct image in this case ? I tried already a factory reset to be sure that way too ...

I will tell my believe and knowledges about HDMI system, tell me if i mistake please, that would help me to identify the problem.

HDMI is a multiplexed digital signal containing all video and audio data multiplexed all in one and divided in 3 channels of data + a clock channel. So the audio gets mixed in any channels too. The switch only serves to select one of the input connector to dispatch its signals to the main HDMI decoder. The decoder is demuxing the data signals and provide all numeric output separated as : R,G,B, H sync V sync, Audio to the Micom section , Micom is dispatching the audio in digital way to the audio decoder.

Then if all input arrives to the decoder it should work completely or not at all, depending a signal slot is corrupted or not token in account but not partially working right ?

One more information, Muteout pin of SIL9125CTU is 0V.

Thanks for your help.

[Davi.p]

Re: Samsung LE40M86BDX no sound on HDMI after a lightning

Have you ever seen a LCD panel datasheet? In the part that explain how the data is composed on the data signals? For example on the line1 there are part of the RED component bits and part of the green component, on the line 3 (its only an example, not right) there are the rest of green signal plus image sync... OK, i have not found in a rapid search the composition of data on hdmi, but its possible that on a single data line there are only sound bits... and maybe 2,3 or 4 bits of the image, so a missing signal may mean missing sound and maybe some missing bits of image... bye..

[yoritomo]

Re: Samsung LE40M86BDX no sound on HDMI after a lightning

I don't know much more about LCD panels, I guess the process is similar.

When i am watching correctly the image of a HD image i can see it has some loss, not really beautiful, as missing details . The image i plain and flowing with a correct speed and colors but poor quality, especially i have tested the menu of my Lacie USB media player, usually the menu is pure and clean on this TV, writings are dirty.
I tested the same movie on my computer which looks very nice and beautiful. No comparison.

[Davi.p]

Re: Samsung LE40M86BDX no sound on HDMI after a lightning

So a missing signal is probable.. Let us to know what you discover...

[CapLeaker]

Re: Samsung LE40M86BDX no sound on HDMI after a lightning

Just for shits and giggles: Did you try a different HDMI source?

[yoritomo]

Re: Samsung LE40M86BDX no sound on HDMI after a lightning

Hello yes i of course tried other HDMI source anyway on other tv they are working fine.

After the replacement of SIL9185CTU and nothing worked i gave up this time. And no luck for a replacement motherboard too.
Thanks for your help all.

[CapLeaker]

Re: Samsung LE40M86BDX no sound on HDMI after a lightning

aww... too bad... did you use hot air to put the new IC back on? Maybe put the old IC back on? Could be that you had gotten a bad replacement IC.