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Samsung LE40A536 constantly restarts itself

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Bambooz:
Yep. Checked the orientation multiple times. With the original EEPROM back in there, it turns on and reboots as before.

flyflytn:
So did you make any progress with this ? I have an LA40N81BDX doing the exact same thing.
Replaced all the caps (4 were definitely fried in the usual section), which got the TV to fire up for.....15 seconds. I can time it to be 10 seconds after the HV to the screen has fired up....so I can hear the HV inverter fire up in 3 or 4 stages in steps, gets to the final stage, wait 10 seconds and then it restarts. The restart will cause the screen to flicker off/on - sometimes once, sometimes 4 or 5 times very quickly.
I've fixed a few plasmas, but this is my first lcd so finding my way around.....
ciao

flyflytn:
I managed to clear my EEPROM (or so I think I have) but still this restarting issue persists.
The service menu says zero hours use now, so I assume all the EEPROM was erased. Anyone managed to fix this at all ?

watteau:
Hello,
Just a thought, are you certain it's the main board causing this problem?
I've had problems with the power-supply giving this effect.
You could try lifting the power-supply 'on' lead going into the power supply output socket
(normally marked PWR ON/OFF, or PS), coming from the main PCB, and supply a switch on voltage from the 5v standby supply via a 4K7, to that pin on the power-supply, and see if the set stays on.
Regards,
John.

flyflytn:
Yes, thats what I was thinking too. I had already tried last weekend but with no load on the board - its only when the logic board is connected that the PSU goes down. So my new test is going to be holding that line high while the whole TV is going.....I'll stick a diode in there to stop any flow to the logic board and have a look with my CRO. But yes I still think its the logic board since the timing is always the same, nothing heat related.

Next stop after that I'm not sure....possibly tracing that on/off line all the way and check components along the way. Thanks for the suggestion, great minds think alike and so do you and I   :wink1:

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