Archive | April 2017

Dead RCA TV

I found a dead RCA RLDED5832A-B on kijiji for 20$. Figured 20$ was a decent gamble on a 32″ TV. I got it home and confirmed that it was indeed dead. When I plugged it in the LED was red on the front but nothing happened when the power button was pressed. I popped off the cover to have a look and nothing was obviously burned. I applied power to the back light to see if there might be any dead leds or bad connections but it lit up fine.

The main board for this TV is numbered TP.MS3393.P81. In this TV it does everything, it’s the power supply, controller, backlight driver. The only other board in there is the tcon board for the panel. After some reading around about MSD3393 based controller boards there was talk about corrupted/failed EEPROM, and it matched my situation, it seemed like everything should be working but it just wasn’t being told to turn on.

I desoldered the memory chip from the board and soldered it with fly wires to a raspberry pi A+ that kicks around my bench. Using the flashrom program it was easy to dump the contents of the eeprom out to a file for a look. The fact that I was able to dump the contents seemed to go against the theory that this chip had gone bad, but who knows.

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I ordered a set of 10 EEPROM chips from ebay for about 5$ (PN W25Q16BVSSIG) and waited about a month. When they arrived I loaded one up with a eeprom bin from a different TV with a similar mainboard, specifically with the same processor, and soldering it down on the board. Semi-success!! The TV lit up and booted, and after struggling through Spanish controls, I was able to get an HDMI signal from my Pi on screen. With the still disassembled panel propped up on my bench it looked like I had a new TV! It was at this point I noticed that the RCA logo on the frame of the TV had somehow turned itself upside down… shit… so had everything else… so the TV that my eeprom file originated from was likely almost identical to mine except for one key detail, the panel was installed 180 degrees to mine.

I was tempted to just deal with this. Maybe install the TV on a wall mount and just suppress my gradually building rage at the upside down RCA logo staring back at me. But this wouldn’t do…. I had searched all over the internet for a BIN file for this specific TV, and despite finding several roms for very similar TVs (there’s a surprisingly large online community of people that like dismantling TVs and dumping their memory contents, go figure) I couldn’t find mine. I did have the rom that I was able to pull from my “bad” chip initially though, and when I compared it to some of the ones from online it looked sort of similar. So I figured why not take a chance just burning the same rom back to a new chip and see if it worked. Well, that resulted in full success!

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I don’t know why that worked, all I can think is that something went wrong with the chip that stopped it from working at the full speeds the mainboard ran at,  but the relatively slow speed I read it at was ok.  Anyhow, now I have a working 32″ TV I need to find a use for…
And if anyone needs a rom file for a RLDED5832A-B you can find one at this link