Hello generous and kind fellow fixers!
I am trying to solve the problem on this set and keep striking out.
Symptom: TV runs fine with good picture for about 15 minutes and then turns off as though the power button was pressed and then turns back on by itself immediately. Then it will repeat the cycle, but takes less time to shut off (5 or less minutes). LED2000 on the logic board is blinking about 1 time per second (maybe slightly faster) WHILE TV IS RUNNING, then it goes off when the TV shuts off, but returns to that same blinking when the TV turns itself back on.
What I've done: Since I've been seeing quite a few similar Samsung Plasmas with very similar or same symptoms being caused by bad solder connections on the Power Supply PCB, I was hopeful this one was going to be the same scenario. I did find some questionable connections (nothing really obvious, though) on the Power Supply PCB, but resoldering them did not help. It seems like this problem must be thermal and sure acted like a thermal solder connection problem.
I then pulled the Y-SUS and found many very suspect solder connections; this is a double sided board and most or all of the fets and such had solder that didn't even flow through to both sides, thus the pins were basically uncovered on the top of the board and there were many cracks forming on the bottom of the board. Alas, resoldering everything had no effect; TV still shuts off in the same way.
I have a good relationship with a supplier who allows returns without restocking fees, so I ordered and replaced the Power Supply and the Y-SUS just to rule them out (still thinking that it must be some bad solder joint somewhere that is thermal and I just must have not seen it or missed it). Sadly, neither board fixed the TV. So, I put the original boards back in.
Then I pulled the X-SUS and inspected it but didn't bother resoldering anything as they looked better than the Y-SUS and Power Supply connections.
Then I surmised that the problem must be with the Main Board, so I froze the Main Board to see if the TV would stay on and no such luck; it still shuts off.
So I come to you here with my hands open, begging for help on this terribly troublesome TV! Thanks in advance!
PS: I haven't tested any voltages yet; I guess I assumed everything would read okay, otherwise it wouldn't be running with a good picture, but maybe I should be checking for a rise or drop somewhere? I'm hoping Tom66 will know!
I am trying to solve the problem on this set and keep striking out.
Symptom: TV runs fine with good picture for about 15 minutes and then turns off as though the power button was pressed and then turns back on by itself immediately. Then it will repeat the cycle, but takes less time to shut off (5 or less minutes). LED2000 on the logic board is blinking about 1 time per second (maybe slightly faster) WHILE TV IS RUNNING, then it goes off when the TV shuts off, but returns to that same blinking when the TV turns itself back on.
What I've done: Since I've been seeing quite a few similar Samsung Plasmas with very similar or same symptoms being caused by bad solder connections on the Power Supply PCB, I was hopeful this one was going to be the same scenario. I did find some questionable connections (nothing really obvious, though) on the Power Supply PCB, but resoldering them did not help. It seems like this problem must be thermal and sure acted like a thermal solder connection problem.
I then pulled the Y-SUS and found many very suspect solder connections; this is a double sided board and most or all of the fets and such had solder that didn't even flow through to both sides, thus the pins were basically uncovered on the top of the board and there were many cracks forming on the bottom of the board. Alas, resoldering everything had no effect; TV still shuts off in the same way.
I have a good relationship with a supplier who allows returns without restocking fees, so I ordered and replaced the Power Supply and the Y-SUS just to rule them out (still thinking that it must be some bad solder joint somewhere that is thermal and I just must have not seen it or missed it). Sadly, neither board fixed the TV. So, I put the original boards back in.
Then I pulled the X-SUS and inspected it but didn't bother resoldering anything as they looked better than the Y-SUS and Power Supply connections.
Then I surmised that the problem must be with the Main Board, so I froze the Main Board to see if the TV would stay on and no such luck; it still shuts off.
So I come to you here with my hands open, begging for help on this terribly troublesome TV! Thanks in advance!
PS: I haven't tested any voltages yet; I guess I assumed everything would read okay, otherwise it wouldn't be running with a good picture, but maybe I should be checking for a rise or drop somewhere? I'm hoping Tom66 will know!
Attached Files
) and have read many of your posts on here (you seem to have a wellspring of knowledge on the mysterious animal that is a plasma) and I can't help but wonder what is going on in that mega-brain of yours in regards to this problem?
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