Philips lcd 32 inch no power

[fuhrer]

Re: Philips lcd 32 inch no power

what kind of multimeter do you use exactly?
analog or digital

[fuhrer]

Re: Philips lcd 32 inch no power

much easier to use a digital one if you're to measure voltage. and an analog one for continuity tests.the weird pair we call it

[mbates14]

Re: Philips lcd 32 inch no power

told you to pay attention to the inverter board.....

[Agent24]

Re: Philips lcd 32 inch no power

What brand of capacitors are used on the boards? I don't believe you've told us.

[weasel440]

Re: Philips lcd 32 inch no power

I'm using a DMM, As for caps I Don't see any bad. They are (Jamicon) & (Su'con) caps. I sent the one board back (2 bad transistors) and ordered another one, should be here today.

[Agent24]

Re: Philips lcd 32 inch no power

Jamicon... probably average. Su'scon are pretty crappy though as far as I know.

Could be you've got some dead ones in the inverter circuit, which aren't showing visible signs of failure.

Got an ESR meter?

[weasel440]

Re: Philips lcd 32 inch no power

No I don't have a ESR meter.
Ty all for bearing with me through my learning experience.

I got the other board in the mail today and same outcome still won't power up. I tested the same transistor (Q209) and I got readings off of 3 leads. This is the way I tested it...
"The base-emitter (BE) junction should behave like a diode and conduct one way only.
The base-collector (BC) junction should behave like a diode and conduct one way only.
The collector-emitter (CE) should not conduct either way."

Like I posted earlier if I remove the one cable - the power light stays on, but no picture. so I then tested for voltage as the manual says, and according to the manual it says replace? I've included a photo of the particular page in question. Flow chart #7 & 8. I have the described voltages +19v & +16v = replace.

Not to offend anyone, I see a couple of suggestions on "checking inverter board" I'm by no means an expert at this type of stuff, but the service manual has you checking / testing on the main board? Where would be a good starting point after the (HOT) side of the inverter board? I've checked for voltages except for out of the transformer, like I mentioned I didn't see anything in the troubleshooting area for the inverter board.

Any help from here would be greatly appreciatted.

[weasel440]

Re: Philips lcd 32 inch no power

No one has any suggestions?

If the power light - lights up and stays lit with the cable unpluged between main & inverter board, would that suggest the main board is good, or could there be a short on the main board as well?

[Agent24]

Re: Philips lcd 32 inch no power

Could mean a lot of things I imagine.

I had an AOC monitor with bad capacitors on the PSU\inverter.

Normally it would switch on, display image for about a second then turn straight off again.

With the panel disconnected, the backlights would stay on longer, giving a white screen, but would still turn off.

I did a replacement of all the capacitors on the PSU and inverter, and it worked perfectly.

Since you have bought a new PSU it's probably not the problem.

At this point I would pull the capacitors on the inverter board and start testing the ESR. Since you don't have an ESR meter, you could just try swapping them out.


Have you checked all the voltages etc as per the troubleshooting steps and checked any parts associated with those steps?

[weasel440]

Re: Philips lcd 32 inch no power

told you to pay attention to the inverter board.....

that was the problem. New / Used inverter board came in the mail today. I probably couldn't have bought the parts to fix mine for the price I paid for the whole working board. ($15.00 usd)

I didn't see anything visably wrong with my old board other than the transformer had solder running down the pins/legs. It must of got hot at one time.

BUT I still have one small problem yet (I think)? One of the TRANS INVERTER HVT-153 is buzzing / humming on the board I got. Not Bad, is this normal or should I replace it with one off my old board? I probably could send it back for exchange. I've circled the part in question in yellow.

[Agent24]

Re: Philips lcd 32 inch no power

It's probably got loose windings.
You can put potting compound or varnish in it I think to stop that.

But it will be easier to replace with a different one.

Unless something else is causing the buzzing...

[shurnapa]

Re: Philips lcd 32 inch no power

Hi, we have the same TV, with a broken screen, one of us should buy the others and put them together.