Polaroid P40LED13 powers up then shuts down

[speedypro]

Re: Polaroid P40LED13 powers up then shuts down

Yup! I will decline. Last time I cracked the screen! It's sooo.....thin. I'll tell the customer I can repair it.

*cant repair

[dick_barton]

Re: Polaroid P40LED13 powers up then shuts down

I've recently repaired one of these with no backlight but it was not a led problem.

I'm sure ReeceyBurger123 had a video highlighting two capacitor to check for possible failure which led me to finding C525 faulty.

Here are the notes I made.

No led backlights.

PFC circuit not running. No VCC for U101 PFC controller (FAN7529). C525 low resistance / capacitance. Replaced the 1uF 50V. VCC now up to 10.5V. Min voltage needs to be 14.5V for PCF to run. Further checks found Q216 (BC327) with collector/base short circuit. Replaced BC327 and set now up and running.

[speedypro]

Re: Polaroid P40LED13 powers up then shuts down

I've recently repaired one of these with no backlight but it was not a led problem.

I'm sure ReeceyBurger123 had a video highlighting two capacitor to check for possible failure which led me to finding C525 faulty.

Here are the notes I made.

No led backlights.

PFC circuit not running. No VCC for U101 PFC controller (FAN7529). C525 low resistance / capacitance. Replaced the 1uF 50V. VCC now up to 10.5V. Min voltage needs to be 14.5V for PCF to run. Further checks found Q216 (BC327) with collector/base short circuit. Replaced BC327 and set now up and running.

I'll check that out when I get to work but in my case, when the tv turns on, the backlight comes on for a split second then goes out and no image on tv; tv is NONE operational. Removing the led wire the tv IS operational, just no backlight. So something is making the tv NONE operational when the led wire is attached to the psu.

[ReeceyBurger123]

Re: Polaroid P40LED13 powers up then shuts down

Sounds to me like a bad connection in the Led strings causing intermitent backlight.

[dick_barton]

Re: Polaroid P40LED13 powers up then shuts down

The fault is different to mine in as much as the set did power up but just no backlight so as ReeceyBurger123 says the leds would need to be checked out.

[speedypro]

Re: Polaroid P40LED13 powers up then shuts down

Sounds to me like a bad connection in the Led strings causing intermitent backlight.

Put it this way, the tv turns off but not standby light (red light). You have to plug the lead out the wall, put back in before you get the red light.

Im sure I wont check any strips lol

[ReeceyBurger123]

Re: Polaroid P40LED13 powers up then shuts down

That sounds normal to me lol, also if you dont want to I would buy it off you haha

[davidpringle]

Re: Polaroid P40LED13 powers up then shuts down

as im going through the threads on here one minute i feel i have an answer for my problem and then i feel more confused lol. My set stays on for 3mins then backlight shuts off, i can see image with torch. Some say its c525 or (c252). I changed for another spare 17ips20, however, no backlight came on, image with torch visable. The spare 17ips20 was a little different though. Im stuck, i dont want the risk of removing screen etc to test the backlights unless i really have too. Panasonic tx 55c400b

[leo-saphira]

Re: Polaroid P40LED13 powers up then shuts down

make sure the part numbers of the 17ips20 is a match as there is many different versions - part no is on the barcode starts as 23xxxxxx etc

[budm]

Re: Polaroid P40LED13 powers up then shuts down

'17ips20' is the blank circuit board P/N, the blank board can be stuffed hundred ways to make a bunch of the PCB assembly for the needed TV models, numbers on the bar code is for the PCB assembly that you need to match.

[davidpringle]

Re: Polaroid P40LED13 powers up then shuts down

So with the original board in this morning tv is on for 6 mins before backlight shut off, leaving tv on visible with torch, and the second time back light shut off after 3 mins. Backlights do light up with led tester on main backlight socket. Something is making a little noise/ buzzing/ high pitch

[dick_barton]

Re: Polaroid P40LED13 powers up then shuts down

Turn the backlights down as low as you can (not the brightness) and see if they stay on longer or even remain on. If that's the case then it is looking like an led(s) problem.

[leo-saphira]

Re: Polaroid P40LED13 powers up then shuts down

So with the original board in this morning tv is on for 6 mins before backlight shut off, leaving tv on visible with torch, and the second time back light shut off after 3 mins. Backlights do light up with led tester on main backlight socket. Something is making a little noise/ buzzing/ high pitch

There is a LED controller IC on the back of thesr boards that needs replacing... cant remember what it is at this momemt in time. Will post back later.