another polaroid 37 flm373b problem

[gmzombie]

ok so ive gotten my hands on this 37 in polaroid and the problem im having is it will sometimes power up to a blank screen, but you can see the backlights come on and sometimes it shows up like the pic below. All scrambled. i took a look at the power supply board and no caps seem to be bulged in any way. im thinking the mainboard but was wondering if anybody else had this problem and what they did to fix it. thanks

[ratdude747]

Re: another polaroid 37 flm373b problem

ok so ive gotten my hands on this 37 in polaroid and the problem im having is it will sometimes power up to a blank screen, but you can see the backlights come on and sometimes it shows up like the pic below. All scrambled. i took a look at the power supply board and no caps seem to be bulged in any way. im thinking the mainboard but was wondering if anybody else had this problem and what they did to fix it. thanks

what brand capacitors?

polaroids are known to have bad cap issues, which is not always visible (the caps sometimes "dry up").

[gmzombie]

Re: another polaroid 37 flm373b problem

sorry for the long wait i was out of town. the caps are mosetly capxon but cap c113 and c112 are nichicon so maybe those have been replaced before?

[gmzombie]

Re: another polaroid 37 flm373b problem

do you think a simple cap kit will fix this issue? i know the capxons arent that good when in comparison to nics, panasonics, and so on.

[PlainBill]

Re: another polaroid 37 flm373b problem

do you think a simple cap kit will fix this issue? i know the capxons arent that good when in comparison to nics, panasonics, and so on.

You are being too generous. CapXons are junk compared to most other brands.

Since no caps are bulging, I won't state that recapping will fix the problem, but it is the most logical thing to try.

PlainBill

[tom66]

Re: another polaroid 37 flm373b problem

I've seen this problem occur when the power supply goes bad. It's due to the 5V going to the T-con dropping out (in my case the motherboard supplied the 5V, from a buck converter - the converter had failed and I rigged a 5V supply up to it but it started overheating and the picture froze with lines all over the image and eventually became the image you show.)

There are two caps on the power supply, 1000u 10V I think, that filter the 5V rail. If those go bad then the T-con will go funky.

[gmzombie]

Re: another polaroid 37 flm373b problem

thank you for your insight. i will try a cap kit first and foremost.

[gmzombie]

Re: another polaroid 37 flm373b problem

ok so i recapped this power supply and i did get better results. i can now get a picture but it still seems distorted. i cant read the menu when i press the menu button but in the big letters if i was on a channel i can read that although not to well. Also on a fuzzy channel the pic is green?

[tom66]

Re: another polaroid 37 flm373b problem

ok so i recapped this power supply and i did get better results. i can now get a picture but it still seems distorted. i cant read the menu when i press the menu button but in the big letters if i was on a channel i can read that although not to well. Also on a fuzzy channel the pic is green?

Remove the LVDS cable and plug it in again. Very common for it to come loose during service of these Proview TVs causing odd symptoms.

[gmzombie]

Re: another polaroid 37 flm373b problem

yup that fixed it.. thanks again for the help.

[gmzombie]

Re: another polaroid 37 flm373b problem

sorry to bring this post from the dead but i got this tv back with an apparent audio issue. sometimes instantly and sometimes it has to warm up but it will get a louder than the sound coming from the tv hum like sound. it appears on all outputs of the tv. anybody ran into this before?

[tom66]

Re: another polaroid 37 flm373b problem

sorry to bring this post from the dead but i got this tv back with an apparent audio issue. sometimes instantly and sometimes it has to warm up but it will get a louder than the sound coming from the tv hum like sound. it appears on all outputs of the tv. anybody ran into this before?

Yeah, bad caps on 24V for inverter sometimes causes this.

[gmzombie]

Re: another polaroid 37 flm373b problem

the only caps i dint replace on the power supply though are the 2 really big ones side by side and one small one close to t104 underneath the small heatsink.

[gmzombie]

Re: another polaroid 37 flm373b problem

bump for an answer about the 24v inverter caps

[gumby1222]

Re: another polaroid 37 flm373b problem

I have the same model TV with very loud noise problems on first boot up (it goes away after about 5 minutes of warmup, but the noise is getting worse). I have not yet taken the device apart to see what capacitors are bad, because this is the only TV in the house and the wife and kids would go stir crazy if it were gone for a day of repairs. If I wanted to just purchase all of the capacitors in one go to have them on hand for replacement, is there a kit or a list of the necessary parts somewhere that I could get?