Samsung LE40R81b not turning on (relay clicking on and off)

[Dannyx]

Good day folks. Got this Samsung LE40R81b TV which doesn't turn on. When I opened it up, it indeed had some bad caps (pun intended ) on the power supply. I replaced those, power supply works like normal now, producing all the correct voltages, however the problem persists: when you plug it in, the LED comes on, the relay clicks, the voltages come up, but no picture is displayed and after a few seconds, the relay drops out and the process restarts. I read in this thread, that there could also be bad caps (pun intended again ) on the main board itself. While mine is not completely identical to the one in the other thread, I DO see some 1000uF caps similar to those. My board is a BN41-00839E. I attached a photo of both the board and the caps in question. His caps were under the shield for the CPU, while mine are out in the open and I got 4 of them, while he only had 2. I see some smaller caps under my shield as well, but not having an ESR meter, taking the shield off would be nothing but a waste of time. Should I try replacing the ones on the outside first? Someone else said it could be an EEPROM issue....I've recently acquired one of those cheapy BIOS/EEPROM programmers from ebay, so I COULD work into that if it proves to be an option. Any thoughts ?

[vinceroger69]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

i think with these sets you can fit a blank eeprom and it rewrites the default data maybe see this thread
https://www.ifixit.com/Guide/Samsung...lacement/14574

[Dannyx]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

i think with these sets you can fit a blank eeprom and it rewrites the default data maybe see this thread
https://www.ifixit.com/Guide/Samsung...lacement/14574

UPDATE: I replaced all of those caps and it did NOT solve the issue. I guess it's on to the EEPROM...no idea where it's located though.

[vinceroger69]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

IC1803 on back of mainboard?

[Dannyx]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

IC1803 on back of mainboard?

The board in the link you provided is not the same, although IC803 appears to be the EEPROM on my board also (ATMEL 740 24c256BN). I don't have a blank one on hand, so I was thinking of removing it, erasing it and putting it back in place (after saving whatever's on it of course). The TV's busted anyway, so no way I could make it worse by doing so

[vinceroger69]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

I would try it nothing too loose there is various firmware around but depends on your lcd panel number etc if its the correct type.

[Dannyx]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

Tried removing the chip and running it through my EEPROM programmer, but didn't get anything off of it. It could be that the chip itself is busted and needs replacing.

[attainteddragon]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

try freezing the chip and see if you can read it then.

[Dannyx]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

UPDATE: I DID manage to read and erase the chip after all: turns out I had it inserted into the 25xxx slot of my programmer, when it was supposed to go into the 24xxx, hence the name. Anyway, now the TV DOES come on and seems to work fine, but only for about 20 seconds - then it reboots and the cycle repeats...thought I'd keep you guys posted.

[vinceroger69]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

theres another thread on this forum with that same issue i will see if i can find it

Edit! No follow up so not sure if new eeprom solved the issue
https://www.badcaps.net/forum/showthread.php?t=16708

[Dannyx]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

I think I found it at one point but never actually got the solution...it sorta died off :|

[vinceroger69]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

its odd your sets sort of working now i wonder if you can find what ic the eeprom is re writing the data from once found that ic clear the eeprom again and freeze spray the other ic then start the set up as it may write more data too the eeprom?

[Dannyx]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

I'll try it with a new chip and see if that makes a difference. If not, I'll have to get a whole new board.

[dskall]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

You could still have a bad cap and causing restart and eeprom corruption. Maybe you can measure across caps in ac mode or if you have oscilloscope for noise.

[Dannyx]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

You could still have a bad cap and causing restart and eeprom corruption. Maybe you can measure across caps in ac mode or if you have oscilloscope for noise.

No scope sadly...what should I be looking out for with the regular meter ?

[dskall]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

Here's a video may or may not help find problem
https://www.youtube.com/watch?v=LvXe0bOF_mk

[Dannyx]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

Here's a video may or may not help find problem
https://www.youtube.com/watch?v=LvXe0bOF_mk

Oh I get it. Neat little trick

[attainteddragon]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

what eeprom reader/writer did you get? i know a couple of us are looking at getting one and any info you have would be awesome.

thanks.

[Dannyx]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

It's not too big a deal and I haven't had any significant achievements with it to be fair - we got it rather cheap from ebay or aliexpress just so it'd be there if need be. I don't have it on hand right now to show you pictures, but it looks like this. The idea is you plug the thing in, install the drivers which I can't recall where my mate got from honestly and then you either solder the chip onto the programmer board itself to access it, or get yourself a little riser board with a clip which clamps onto the chips directly so you don't have to solder them anymore - looks like this, but we had to get it separate from the programmer. It presumably also allows you to read the chips while still on the board, but I tried it several times and it didn't work, so either way you pretty much HAVE to remove the chip, though that could be down to individual chips or the programmer itself. The trouble is not so much accessing the chips, but having something to write back on them, as finding the correct firmware is difficult or impossible. You might have some limited luck erasing the chip and putting it back in, like I did here, but as you can see it only worked half-way as the TV still power cycles. For computers, a blank BIOS chip is obviously never gonna turn on that motherboard again, so make sure you back up what's on the chip first and THEN mess with it - you might even get lucky to find the firmware somewhere, like we did for a Toshiba laptop.

[vinceroger69]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

what eeprom reader/writer did you get? i know a couple of us are looking at getting one and any info you have would be awesome.

thanks.

I also have the same programmer as dannyx but also have one like this although you can get them a lot cheaper this was the first link i found with all the accesories
http://www.ebay.co.uk/itm/TL866A-Uni...sAAOSwal5YEdaJ