Dead 31MU97-B monitor, power board OK.

"Oleg Gritsev



Rep: 97




2


1"

"I had this issue and came across this blog that helped fix it with a multimeter and an hour of my time. https://integer13.wordpress.com/2018/04/...

Hope this will help others too."

"I had the same issue. 31MU97B Monitor died when the UPS was turned off while it was powered on. No lights would light up, nothing on the display. All the voltages looked good. No parts looked bad. So I bought the eeprom replacement from:

http://www.coppelltvrepair.com/p/1483/lg...

Swapped this out and I'm up and running again. Your mileage may vary.

It seems strange that a read only eeprom chip would die, so I was very skeptical to start with, but this did fix it."

"So, my LG 31MU97-B has developed this problem again. I wonder if it is possible in this old thread to establish clearly the procedure to fix the most probable cause.

So, it’s the IC205 on the mainboard – quite easily found (once you can get to the mainboard – I’ve a spare one, of course). This chip is an MX25L8006EM2I-12G.

I buy a CH341A SPI Programmer with SOP8 clip.

Can I then follow this guide?

https://www.win-raid.com/t4287f16-GUIDE-...

I plug the programmer into a USB port and correctly connect the clip (connected to the programmer) to the EEPROM IC205 and issue on my Linux computer command line:

$ sudo flashrom --programmer ch341a_spi -r backup.bin

If I get no errors, I then issue the command:

$ sudo flashrom --programmer ch341a_spi -w lg31mu97.bin

having downloaded lg31mu97.bin from the link given in the WordPress blog:

http://aleksikoski.com/temp/lg31mu97.bin

Actually, I’m not too sure you’d be too advised to do this straight out. The CH341A would supply the EEPROM chip IC205 with the required supply voltage of 3.3V. However, the CH341A appears to operate at 5V and supply programming signals at around that voltage to the chip it is programming. It may therefore damage the chip we are trying to reprogram and other devices on the mainboard. Apparently, it’s possible to make the CH341A use the 3.3V supply at which it will still run. This solution involves wire and solder.

Got mine fixed again. Pete of Pete’s Computers (Manchester, UK) reprogrammed the IC205 chip for me.

http://peterscomputers.co.uk

Comments and advice very welcome, of course."