Re: Samsung 48J6400 fail to turn on, loop boot

Quick update: the problem is indeed at the main board. Left the PSU plugged to mains and the main board unplugged for 6+ hours, and when I returned the backlight was still on. Plugged the main board to the PSU and the TV worked for 3 minutes, then turned off backlight, and to minutes later rebooted. For three times it managed to turn on (I briefly heard sound) from the TV channel), but rebooted again, until it was not able to turn on anymore.

Re: Samsung 48J6400 fail to turn on, loop boot

I've read in some places that when the TV goes to a boot loop, the EEPROM should be responsible, and replacing it would fix the problem. Could an EEPROM replacement do the trick? Or is the main processor the most likely faulty part, since the TV does boot, just doesn't stay on? Getting an EEPROM replacement shouldn't be much of a problem, but if I had to replace the main processor, it should be better just to get a new main board.

Re: Samsung 48J6400 fail to turn on, loop boot

I already did that, the backlights stays on, anytime I test. So this is what I've learned until now:

- the longer it stays disconnected from mains, the longer it will stay on until it turns off (backlight first, then TV goes to reboot loop);
- disconnecting the T-CON board and/or the backlights has no effect;
- the backlights and the PSU side responsible for supplying it's power are fine;
- it doesn't seem to be an overheating problem, since a fan blowing air directly to the boards made no difference....

Re: Samsung 48J6400 fail to turn on, loop boot

Some more interesting troubleshooting:

- I managed to get it working (it stayed unplugged from mains for some hours) but suddenly the backlights turned off, and I only got sound. Everything else was working: could change channel, increase volume, etc. Don't know if the panel was working, though;
- when I turned it off and on again, the backlights were on for a few seconds, then turned off again, still got sound;
- after a couple of times turned it on and off, it went back to the initial state: turn on for...

Re: Samsung 48J6400 fail to turn on, loop boot

Just tried booting the TV with the T-CON board disconnected after some time with the TV disconnected from mains, and the TV booted just fine (no image, of course, but the optical output was lit and the standby LED stopped blinking). When the TV gets to the boot loop, unplugging the T-CON board would not make the TV boot, so I'm guessing it is safe to say that the T-CON board is not defective.

I think I'll get the chance that the TV is booting and clear/update the firmware. Since my firmware should be the latest, any advice...

Re: Samsung 48J6400 fail to turn on, loop boot

But couldn't just the part of the PSU that lights up the LED backlight be OK, and there is some problem with the other part? The fact that when I discharged the big caps I got "further" on the booting process made me think that "rebooting" the PSU made things a little better, just as leaving it unplugged from mains a few hours made it boot normally (it tried again this morning, turned on and off twice normally, as there was no problem at all).

I've read the post, but my problem is a little different....

My Samsung 48J6400 started behaving strangely: it would take a hard time to turn on (would cycle from on and off a few times before I got it to stay on), until one day it decided not to turn on, just flashed me the power led (blinked twice briefly for 5 times). So I decided to take it to the repair store.

Before I took the TV to the repair shop, I was thinking the problem was work the PSU, since the TV was having a hard time to boot prior to not booting at all. But the diagnosis was that the culprit was the panel, and it would cost a new TV to repair it.

The thing...

Re: New Members - please post your introductions here

Hi there! Just trying to avoid expanding lots of $$$ to fix electronics that just had a few bad caps, and just enjoying and learning along the way.