Samsung Odyssey CRG9 not powering on

[unimatrix93]

Hello everyone, I'm stuck with the aformentioned gaming monitor.

PSU: BN4400976A
MB: BN41-02699A

Symptom: NO sign of life. No power led, no backlight or display.
Diagnostics:
- PSU outputs 12V volt when connectred to MB. PS ON is 7V when disconnected, goes .40V when connected to MB.
- EN signal stays low on 12V buck converter IC so 0V on output when EN pin is connected, all other power rails looks okay.
- Bypassing EN signal by floating EN pin on 12V buck converter results in 12V on output, however still no lifesign.
- T-CON looks okay, no short found only a slight buzzing noise when 12V is there.

What I tried:
- Replacing the Buck converter IC (IC1401 \TPS54540). When the new IC got installed the backlight turned on for a few seconds but it happened like 2 times, then the original symptom came back.
- Tried to start it up with the LCD or T-CON disconnected by no change in the symptoms.

12V rail's EN signal source is the CPU, might be CPU error? Someone mentioned on reddit that the CPU might be stuck in an error mode, where it won't leave this state. Other power rails EC signal is present, altough a bit high 1.7V.

What else should I try\check? Could reflash the flash memory, not tried that one yet.
What do you guys think?

Thank you!

[lotas]

If the resistance on the HDMI lines is low, then this is very bad. since they go directly to the processor, this means the processor is dead, only replace it or look for a donor on the motherboard, the dump checksum should be shown by the programmer program itself, consisting of 4 characters.

And low resistance or short circuit on signal lines occurs due to a “hot plug” cable between devices!

[lotas]

Check the signal lines on HDMI, DP, USB for low resistance or short circuit to ground, if the monitor has not been updated with software, then you can read the dump spi flash and check the dump checksum, it is indicated on the tag.

[unimatrix93]

Check the signal lines on HDMI, DP, USB for low resistance or short circuit to ground, if the monitor has not been updated with software, then you can read the dump spi flash and check the dump checksum, it is indicated on the tag.

Dear lotas,

I checked the signal pins of the ports and I found this:

15 ohm resistance to ground, while the other signal lines has high resistance. It's on the HDMI port.
Also I saved the bin file from the SPI flash, I got this value after applying Get-FileHash: 8E9DE8A4B2A1F60ED02BA1027C8B1638FFCC3A7E6A46214BC1EC7ADEE288BE9E

[lotas]

If the resistance on the HDMI lines is low, then this is very bad. since they go directly to the processor, this means the processor is dead, only replace it or look for a donor on the motherboard, the dump checksum should be shown by the programmer program itself, consisting of 4 characters.

And low resistance or short circuit on signal lines occurs due to a “hot plug” cable between devices!

[unimatrix93]

If the resistance on the HDMI lines is low, then this is very bad. since they go directly to the processor, this means the processor is dead, only replace it or look for a donor on the motherboard, the dump checksum should be shown by the programmer program itself, consisting of 4 characters.

I loaded up the bin file with asProgrammer and NeoProgrammer too and I couldn't find the checksum value, I'm porbably blind.

However, with your help at least I know that where is the problem.
I even tried to tape down signal lines on the T-CON (suspecting a panel short). All I had achieved was the back light and LCD coming on for a few seconds, but turning off completly later. Even when it came to life there was no OSD, power led, or anything. And had to completly power cycle the thing to replicate it. Also, VGH, VLH were also present despite no life on display\BL. So the T-CON is probably still good.

Do you know a reliable source for this CPU? SE16U201-MST. If not, I will look for a new mainboar probably.

[lotas]

I don't know the suppliers, but you can get a processor from China, either used or defective (it will look like new, unused!), you'd better find a donor, of course, a board with a broken screen, I've seen a lot of them sold on ebay, but You also need to be careful, they can sell you with the same diagnosis.

Yes, the most expensive thing about this monitor is the matrix, and 99.99% of it was not damaged!

[unimatrix93]

I don't know the suppliers, but you can get a processor from China, either used or defective (it will look like new, unused!), you'd better find a donor, of course, a board with a broken screen, I've seen a lot of them sold on ebay, but You also need to be careful, they can sell you with the same diagnosis.

Yes, the most expensive thing about this monitor is the matrix, and 99.99% of it was not damaged!

I found some CPU on aliexpress, but I don't think it worth the cost\time\labour with BGA. Also found a maiboard in Russia, but I don't know the shipping cost to Hungary. Will look around locally and on ebay for a mainboard.

Anyway, thank you very much for your help!
I will upload the dump file to the site, maybe someone will find some use to it.

[lotas]

Ok !