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Samsung LE40A536 constantly restarts itself

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Bambooz:
Hi!  :sign0144:

Stumbled across your forum while searching for the PSU/Inverter board (IP-211135A / BN44-00199A) for this hunk of junk.

TV: Samsung LE40A536 40" Full HD LCD
Mainboard: BN41-01145A ("530_NORMAL_idTV")

All PSU caps have been replaced with low-esr Panasonic/Matsushita and a few Rubycon, and some horrible soldering from a TV tech (?) before me has been fixed up. I even replaced every single tiny 10µF 50V cap (i was in there anyways.. so why not.. knowing what crap caps samsung always uses..)

TV turns on fine, picture is perfect, but it automatically turns off / goes into standby after 15 or so secs and restarts immediately.
Selected source doesn't seem to matter.
You can turn the set off (standby) within the ~15sec timeframe when it works normally.

In short: everything seems to work fine (functions wise), but it constantly reboots itself.

Read about the eeprom trick, and went hunting..
little 8pin sop chip on the solder side of the mainboard where the CI card slot is.

Chip markings Read:

ATMLH0834
2EB 1

google search lead me to this
http://akizukidenshi.com/download/at24c256b.pdf

Part marking scheme fits perfectly, so it's a AT24C256B Two-wire Serial EEPROM. bingo.
Soldered 2 wires to pin 5 and 6, reinstalled the whole mess, twisted wires together, plugged the set in and as expected, it didn't turn on. Removed the short on the two wired, got the TV out of standby aaaand.. reboots after 15secs  :41:

Bad eeprom? Completely different problem?!
Or am i just doing the reset/delete procedure wrong?

*???*

I'm lost..

Any ideas?


Patrik

fix2003:
i find it best to use new blank eeprom :051bye:

Bambooz:
That would probably be the best solution (if it works that is), but i'm having quite a few difficulties finding one locally.

Getting one from china via ebay (actually a 5 pack or more) is no problem. Getting one locally means paying 12eur a piece (wtf are they smoking?!) or having to try to kinda shove a dip package where a sop is supposed to go.. no fun.

I've put the set back together for now (need room) and left the 2 wires soldered to the eeprom hanging out of the side of the case. Playing with them while in standby (randomly shorting them) somehow got it to turn on and actually stay on in DTV/DVB-T/Freeview mode. It's been running for several hours now without a hiccup (apart from the usual crappy DTV picture and blocky-ness), but i fear if i turn it off and back on, the same stuff is going to start all over again :/

I'm gonna hunt around for an eeprom. I just hope that's all there is to it..
If not, I'm running out of options.. replacement mainboards are listed in several shops, but none of them has them in stock.

Patrik

edit: while playing with the 2 wires sticking out, i tried getting into the service menu once, and I noticed that I've somehow managed to reset the ~5900 power-on/lamp hours I saw previously to zero

sparky:
hi
have you checked the tact switch on front of tv
standby button had a lot of problems you can disconect plug and try
dave

Bambooz:
Tried that today (why didn't i think of this?! ). Disconnected the whole front panel button board cable. Same thing :(

As a little "update".. Youtube video (mainly to see if there's anyone else with that problem)
http://www.youtube.com/watch?v=xlfDREBcevs

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