Polaroid TLX-04244B

[2011srg]

hi there i have this polaroid 42" TLX-04244B flat screen it turns on for a split sec and then goes black i hear a buzzing sound for a couple secs right before the screen goes black the power light stays blue so its gettin power, and if i hold a light up to it I can see picture, what is the problem plz help me fix this so i can have a tv again thanks

[tom66]

Re: Polaroid TLX-04244B

Can you post some high resolution pictures of the inverter slave and inverter master boards? Specifically around the connectors to the bulbs.

[2011srg]

Re: Polaroid TLX-04244B

Yes, please give me a few, I'm having problems with my camera

[2011srg]

Re: Polaroid TLX-04244B

Here are the close ups

[tom66]

Re: Polaroid TLX-04244B

Okay, do you have a multimeter?

[2011srg]

Re: Polaroid TLX-04244B

Yes I Do

[tom66]

Re: Polaroid TLX-04244B

Okay, set your meter to 20k ohms, and measure the resistance between the pins in each of the red circles. We are trying to identify a faulty transformer. Note: You must do this while the TV is off or you could damage your multimeter.

Also, is there only one lamp connector? Are there any other inverters? I also find it strange that both terminals of the connector are connected to the same trace...

[2011srg]

Re: Polaroid TLX-04244B

Just to make sure i do this right i ground the black one and use the red one right? If so they all give me 0.04 but the one on the end of the board the left solder point does nothing .

[tom66]

Re: Polaroid TLX-04244B

Just to make sure i do this right i ground the black one and use the red one right? If so they all give me 0.04 but the one on the end of the board the left solder point does nothing .

No, you should place one probe on one pin and one probe on another. It does not matter which way around. 0.04 is very low.

[2011srg]

Re: Polaroid TLX-04244B

Ok so the one on the left does nothing and the one on the right jumps from 1.32 to 0.04. I understand that the t.v has to be off but does it make a difference if its plugged in?

[tom66]

Re: Polaroid TLX-04244B

Ok so the one on the left does nothing and the one on the right jumps from 1.32 to 0.04. I understand that the t.v has to be off but does it make a difference if its plugged in?

Yes it does make a difference if it is plugged in. The inverter outputs about 3,500V for a TV of this size and will fry your multimeter. It MUST be unplugged/off to do the measurement. I prefer to cut the power at the mains just in case it tries to turn on.

[2011srg]

Re: Polaroid TLX-04244B

And yes it has 2 inverters the Master and Slave, if this is your question above. Sorry for all the Questions this is the first time i've done something like this

[2011srg]

Re: Polaroid TLX-04244B

Ok it was unplugged when I did the test.

[tom66]

Re: Polaroid TLX-04244B

Can you repeat the test for the other inverter?

The results so far are inconclusive. The transformer that doesn't read anything might be faulty but I couldn't be certain

Don't worry about asking too many questions - only one way to learn!

[2011srg]

Re: Polaroid TLX-04244B

I repeated the test on both of them and got the same thing for both the one on the left give me nothing but right ones jump up and down from 0.00-19.00 now

[tom66]

Re: Polaroid TLX-04244B

I repeated the test on both of them and got the same thing for both the one on the left give me nothing but right ones jump up and down from 0.00-19.00 now

What range did you set your meter on? Can you post a picture of it in that setting?

[2011srg]

Re: Polaroid TLX-04244B

Here you Go

[tom66]

Re: Polaroid TLX-04244B

Okay, so I'm stumped, that's the right setting, but I'd expect results of "6000" or something for typical inverter transformers. Try again on the 200k range, but that would be very high for those types of transformers.

Another test. While the TV is off, disconnect the slave inverter bulb connector. Turn on the TV. Do you hear the buzzing noise and does the screen light up? Try it with the master board (reconnect the slave). Does the same thing happen? The board that does not produce the effect is probably the bad one.

[2011srg]

Re: Polaroid TLX-04244B

Ok so I did another test and the left ones still nothing and now with using the 200k the right ones jump from 173.3 to 0.01.

I also tried disconnecting the slave and turning on the t.v no light and no buzzing and did the same with the other one and the same thing they both have to be plugged in for the light to come on.

[2011srg]

Re: Polaroid TLX-04244B

The frist pic is on 200 and the second one on 20K. Just making sure this what you are wanting me to do, because i feel like i'm doing something wrong.