EU55JS9000T black screen and sound good

[Davi.p]

Re: EU55JS9000T black screen and sound good

I have few time now to read back all, but since inductors shows no apparent power supply problems, and the hawk p that is the main processor i think, and it is heating a bit, then probably there is cpu soldering problem, i think it is not sending image to the tcon, the tcon that controls backlight on the basis of the image content, sends an almost black signal level to it (see back the 0,04v on p dim)..

[totof]

Re: EU55JS9000T black screen and sound good

I have few time now to read back all, but since inductors shows no apparent power supply problems, and the hawk p that is the main processor i think, and it is heating a bit, then probably there is cpu soldering problem, i think it is not sending image to the tcon, the tcon that controls backlight on the basis of the image content, sends an almost black signal level to it (see back the 0,04v on p dim)..

Yes, I also thought about that, a bit like a certain laptop motherboard. This could be any component on the chain (Hawk-P, Hawk-US or Hawk-N)
The only thing that could make me think that it is something else is that the backlighting is cut off immediately after connecting the cable while the Hawk components have just been powered and are not yet initialized and operational.

[Davi.p]

Re: EU55JS9000T black screen and sound good

i cannot know the complex architecture of such a tv set due to the lack of manuals, but i guess the boot sequence and screen driving sequence is different if you connect the OCB at hot or at cold, i think on the back of tv there is a second main board with something like a subtitute cpu with few tasks..

[lotas]

Re: EU55JS9000T black screen and sound good

Yes, I also thought about that, a bit like a certain laptop motherboard. This could be any component on the chain (Hawk-P, Hawk-US or Hawk-N)
The only thing that could make me think that it is something else is that the backlighting is cut off immediately after connecting the cable while the Hawk components have just been powered and are not yet initialized and operational.

Samsung has implemented this way, even on regular TVs, when the motherboard is disconnected, the backlight will be on constantly and when a faulty motherboard is connected, the backlight will go out, and here, like you, there may be a problem with the eMMC (the firmware cannot load).

[Diah]

Re: EU55JS9000T black screen and sound good

5 pages right now... and the answer was at POST #4 & #8

[nomoresonys]

Re: EU55JS9000T black screen and sound good

So what's up, is it solved or what?

[Davi.p]

Re: EU55JS9000T black screen and sound good

Lotas, first post states sound is good, freetnt tv is audible, so no software problem for me...
as per diagram in post 82 Hawk N is responsible of driving TCON and therefore backlight levels, but there is also an SPI flash memory connected to it that can be polluted..

[totof]

Re: EU55JS9000T black screen and sound good

So what's up, is it solved or what?

No it's not solved (unfortunately)

Lotas, first post states sound is good, freetnt tv is audible, so no software problem for me...
as per diagram in post 82 Hawk N is responsible of driving TCON and therefore backlight levels, but there is also an SPI flash memory connected to it that can be polluted..

The TV works well, I can hear the sound from the TV (TNT tuner source). The sound comes about 10 seconds after plugging in the OCB cable.
So I don't think it's a firmware issue.

[Davi.p]

Re: EU55JS9000T black screen and sound good

not the main firmware but the spi one yes maybe

[totof]

Re: EU55JS9000T black screen and sound good

I can extract the contents of the spi but personally I won't know how to do anything with it

[Diah]

Re: EU55JS9000T black screen and sound good

ONE BOX CONNECT... are the heart of Video and Audio wave Signal... Main boards CPU just process it to feed Panel... if Video wave Zero value... screen remain black for ever. even with out Connect box. end.

[Davi.p]

Re: EU55JS9000T black screen and sound good

must to find a source of the content and rewrite it, not extract anything

[totof]

Re: EU55JS9000T black screen and sound good

Here is the dump of the SPI flash of the OCB card.
Maybe one day it will be useful to someone on this forum.

[Davi.p]

Re: EU55JS9000T black screen and sound good

your document speaks about 2 spi roms, to be aware of which one to process..

[totof]

Re: EU55JS9000T black screen and sound good

your document speaks about 2 spi roms, to be aware of which one to process..

Yes there is also a EEPROM on the OCB board and a SPI on the TV mainboard.
Here are the dumps of these CI.
A lot of 00 on the mainboard TV SPI.

[Davi.p]

Re: EU55JS9000T black screen and sound good

i watched better your block diagram, i see now the separation Ocb/back board, things short, i suspect bad ocb to tv connector solderings.. reflow them all with little new tin.. both ocb & tv sides

[totof]

Re: EU55JS9000T black screen and sound good

I have already checked the continuity of all the signals with a multimeter with the cable plugged in.
No problems detected

[lotas]

Re: EU55JS9000T black screen and sound good

Here I found dump OC eprom and spi from "48". Try it, maybe you'll get lucky.

[Davi.p]

Re: EU55JS9000T black screen and sound good

the best thing you can do is to connect a pc to the debug port and see the log, other than this you can try to access service menu through debug port and do a service reset..

[totof]

Re: EU55JS9000T black screen and sound good

Thank you lotas, I will try tomorrow