T.SK105A.03 monitor/TV board - Page 1
Forum section: electronics / general

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: March 14, 2024, 10:32:59 am
content: I recently acquired a faulty Thinlerain 13in monitor. The fault was that nothing appears on the display. The backlight comes on but flashes every few seconds anlong with the power LED as if the board is re-setting itself. There is nothing obviously wrong with the PCB and the two capacitors looked fine, but I replaced them anyway but no change.The PCB is marked T.SK105A.03. A Google search throws up several of them and it appears they are a cheap 'universal' replacement PCB. It seemed to make sense not to waste too much time and simply replace the PCB. The PCB requires firmware to be loaded according to the display type and resolution using a USB stick. I purchased a replacement and found the appropriate firmware for the resolution of this display panel which is 1366x768. The USB stick was formatted with FAT32 and the .bin file and the md5 has file dropped on to it as the instructions and online videos indicated. The USB stick was then plugged into the USB port and the board powered on. Unfortunately the PCB does not respond as expected with a flashing power LED. The LED just stays on steady. I asked the seller for further advice but I might as well not have bothered as they seemed to have no idea about firmware, despite instructions being included in the listing.I purchased a second board just in case on the off chance this one was faulty. Same problem.At this point I should probably just throw the lot in the bin and write it off, but want to give it just one more shot so am looking at other options. The original PCB as well as the replacement have a 25Q32 memory chip on board. It occurred to me that maybe this can be read and the contents copied to the new PCB. How would one go about doing this? I do have an EEPROM reader which I need to dig out, but would I need to remove the IC from the board, or can it be read in situ? Ideally I suspect it would be safer to read its contents before trying to remove it. Removal should be no problem with hot air, but there are other tiny SMD components around it that I am worried about inadvertently blowing away. Lifting pins might be a safer option but even that risks damaging the PCB.Even so, I am not sure whether there is programming on the MCU chip itself. It is marked UNISOC UTS6710-X. I have found supplies on Alibaba, but no datasheet as yet.An insight on how to approach the matter would be appreciated.

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: March 16, 2024, 03:14:09 pm
content: I dug out the TL886II programmer and I think I have been able to read the content of the 25Q32 chip. I first read it in-situ using a tweezer probe which seemed to go OK. The content looks consistent with although not identical to the firmware .bin file I downloaded a while back. I then removed the chip from the PCB and tried to read it again, this time using the 200-209mi SOP8 socket adapter. Initially I got a different md5 hash but after re-seating the chip in the adapter got two reads with the same md5 hash as the in-situ read. I am reasonably confident that I have a good copy of the data on the original monitor pcb.The next step was to try and program the new board using the first file from the first in-situ reading. The programmer went through the motions but finished with an error. The chip ID seems to be incorrect: 0xFFFFFF instead of 0xEF4016. I tried it with Check-ID unchecked but still ended up with a blank chip. I am unsure why that is?