JVC AV-36950 Doesn't power on. Keep it or junk it? - Videokarma.org TV - Video

MRX37 · #1 06-11-2008, 06:51 PM

Okay, I found this 36" JVC TV model # AV-36950. It won't power on. I keep hearing this clicking noise when I try to power it on.

I'm wondering what's causing this, and whether or not the repair is easy.

If it's just a bad cap or resistor, I'll hold onto the TV, assuming the CRT is still in good shape.

*zenithfan1* · #2 06-12-2008, 12:08 PM

Sounds like the power supply, I have a 27" Teknikka that is doing the same thing. I too am wondering if I should keep or junk.

MRX37 · #3 06-12-2008, 04:43 PM

I heard it mioght be a bad cap in that JVC Tv, but i can't find anymore about it.

MRX37 · #4 06-13-2008, 10:25 AM

I tried the TV again this morning, and there's no change. There's this click that happens about once a second, and it continues until I unplug the TV. I think the clicking is coming from a relay.

It seems like the TV wants to turn on, but that something's preventing it from doing so...

radiotvnut · #5 06-13-2008, 11:13 AM

Some sets have overload protection. There may be a shorted diode in the power supply or a shorted horizontal output transistor keeping the set from powering up.

waltchan · #6 06-13-2008, 12:41 PM

How old is the TV? If its made in the 80s, I say keep it. It's it's made in the 90s or 00s, junk it.

MRX37 · #7 06-13-2008, 01:10 PM

Quote:

Originally Posted by radiotvnut

Some sets have overload protection. There may be a shorted diode in the power supply or a shorted horizontal output transistor keeping the set from powering up.

Could I test these with a multimeter?

Quote:

Originally Posted by waltchan

How old is the TV? If its made in the 80s, I say keep it. It's it's made in the 90s or 00s, junk it.

The TV was made in 1998.

I don't want to junk it if I can get it to work without too much trouble.

radiotvnut · #8 06-13-2008, 03:15 PM

Yes, you can use an ohmmeter. Any cheap DMM with a diode test function should work.

MRX37 · #9 06-13-2008, 03:39 PM

Okay. I'm guessing it would be a fairly large black diode, probably not some tiny hard to see glass diode right?

If so, then I'll test every large diode on the board. I assume they don't need to be unsoldered, since all it is is a one way gate.

My guess is with an ohm meter, a good diode should have no ohm's when testing one way, but infinite ohm's when polarity is reversed.

radiotvnut · #10 06-13-2008, 03:48 PM

With a DMM on the diode scale, you should get a reading one way and nothing the other way. Same is true with an analog meter. If you get a reading both ways, unsolder the part and re-check it.

On the horizontal output transistor, you will get a reading both ways between the outer pins. This is because of the secondary winding of the horizontal driver transformer. If you get a reading both ways from the center pin to the outer pins, the transistor is shorted. The transistor may have went on it's on, or, the flyback transformer may have failed.

The black diodes would be my main concern; although I have seen the little glass diodes short.

MRX37 · #11 06-14-2008, 03:13 PM

There's a lot of diodes on this TV that are in hard to reach areas.

If someone with a SAMS for this TV could give me some more accurate info, I'd be grateful.

I pulled out and tested a large 3 pin transistor which has "D2539" on it. The highest ohm reading is 23.2. The only other reading I get is 0.005 ohms. Is this transistor bad?

EDITY: Okay I'm giving up on this TV, cos I found a 56" RCA projection TV that works pretty good.