Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

[budm]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

Yes, I saw that link last night when I searched the forum using the CMO inverter board model number, in that thread, the OP does not have the 24V for the inverter due to blown 0.22 Ohms fusible resistor int eh power supply board.
The OP also said this "
ADDITION : The 4 blinks then steady Red Power LED is NOT an error code. It did the same thing every time i turned it on. So my guess is, it is a normal start-up procedure"

He probably should remove the glues so he will not have bad brown glue problem in the future.

[triplefour]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

ok i removed wire 14 and didnt notice any difference. i cant get the backlight to come on at all anymore even for a moment...

[budm]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

That is fine, just want to be sure that it is not using the PWM line. Did you recheck all the fuses on the inverter board?

[triplefour]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

i see 24v on both sides of all fuses. but with the power off and measuring ohms i get really high resistance that just keeps climbing... whats going on there?

[triplefour]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

could you tell me what you mean by making sure its not using the pwm line? what is that line for?

[triplefour]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

when i was making the voltage measurements on the fuses, the backlight did try to turn on..it flickered on and off a few times

[triplefour]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

i would like to test the bulbs but the only spare bulbs i have dont have a matching connector

[budm]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

"when i was making the voltage measurements on the fuses, the backlight did try to turn on..it flickered on and off a few times" You mean one of those white fuses on the inverter board, it sounds like you have bad connection, try using plastic rod of some sort and press around the board to see if you can make the lamps to come on.
Can I see good FOCUSED STRAIGHT SHOT pictures of the INVERTER board, then pictures of section of the board (may be in 4 sections) so I can clearly see the traces and the components?

[triplefour]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

will do, and again thanks for all your help!

[triplefour]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

wish i had a better camera... but i guess its pretty good for a phone.
to get the best pics i take the board outside and put it in sunlight on the hood of my car (that needs a wash)

anyway heres the inverter pics

on a completely unrelated note, what the hell is this guy doing???

[triplefour]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

i tried pressing all over the board with the plastic end of one of my screwdrivers but i was unable to get any response from the backlights...whats going on here? it looks to me like all the voltages and ohms are correct on anything i can think of... yet no backlights... is the only thing left to test the lamps themselves?

[budm]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

The way it works is this, if there is at least one bad lamp that is broken or not connected to the inverter board, the inverter will have to start up and try to light the tubes, if in the first 3 seconds, if the protection circuit detects no current draw (lamp not connected) or no constant current draw after firing phase (bad lamp), or too much current draw (bad lamp) for any one of the tube, the circuit will go into shut down. That is why you should see the lamps at least flash on first since not likely that all the lamps can go bad at once then shutdown.

[triplefour]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

well im not even seeing them flash on like that. once in a while it will kind of do that, but its not repeatable at all. most of the time no lights flash at all. how can i be sure if its the lamps or the TCON ?

[triplefour]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

ive tried disconnecting one at a time, and ive also tried having only one hooked up, and tested each on individually, nothing got a flash out of anything

[triplefour]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

ugh 2 posts ago i meant to say inverter, not TCON
but anyway... what can i try next? pretty stuck here :/

[selldoor]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

i noticed while testing the transformers, that some of them would test good using the solder joints but on some of them i had to go closer to the legs to get a proper reading. could this be a sign of weak solder joints causing the problem?

Yes - I would reflow all the joints on all the transformers some dont look too clever and also reflow the capacitors while you are at it.

[Caleb]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

i see 24v on both sides of all fuses. but with the power off and measuring ohms i get really high resistance that just keeps climbing... whats going on there?

you might try putting your ohm meter in amps mode and testing across that fuse to see if the inverter will kick on, sounds to me like a defective fuse, maybe the filament has cooked just enough to go high resistance or possibly the trace is cracked near there somewhere.

[triplefour]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

its not just one fuse though...theres like 12 of them. and what exactly did you mean?
to be honest i havent done any tests with my dmm in amp mode. not really sure how that works. i can switch it over to 10A DC but where do i put the probes to do this test you speak of?

and i think i will try some reflowing of some joints. what is the best way to do that? just heat them up and let them cool again? or actually remove the solder and resolder everything?

[budm]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

I am beginning not to trust the Ohm reading on those fuse, they are less than one Ohms each, I would try resoldering the fuses and recheck the resistance again.

[triplefour]

Re: Samsung LN-T3242H works fine for a day, then wont turn on. intermittent.

ahh i was looking at the wrong thing again. the 12 things i thought were fuses are actually smt capacitors. i found the fuses. theres 4 of them, and they all check out with less than 1 ohms