Sharp LC-52D85U Won't turn on

[birdboy385]

Ok i will admit i haven't done anything to this tv other than plug it in. This tv as soon as i plug it in, the green power light will start blinking and do so infinitely. the tv itself will not boot, no backlights, no screen no sound. Before i start tearing this tv apart, I wanted to hear if there was anything common that people might know about. As soon as i clear my workstation i can tear it apart to look for issues.

[budm]

Re: Sharp LC-52D85U Won't turn on

Download the service manual and see if it has error codes:

[birdboy385]

Re: Sharp LC-52D85U Won't turn on

no sarcasm at all i can't believe i was dumb enough not to think of that lol. I swear i'm not usually this basic with things. I'll take a look and see what i find. Thank you for finding this for me.

[birdboy385]

Re: Sharp LC-52D85U Won't turn on

hmm i found the error codes section but none of these seem to match my issue. as far as i could tell the light will blink until i unplug the tv.

[drkthundr]

Re: Sharp LC-52D85U Won't turn on

I have a LC46D85U TV that does the same thing. The code on mine is power 2 / opc 1 per second. The one thing we have in common is our TVs have the same power board. I've had no luck finding a schematic for it anywhere online.

[birdboy385]

Re: Sharp LC-52D85U Won't turn on

ok so slight update. I held the power button in as it was blinking then the light rwent red . if i hit the power button again it would go orange then the backlight would come on for about half a second id say then would go back off.

[nicholas1110]

Re: Sharp LC-52D85U Won't turn on

This model is well known for the backlight board to become not seated fully. There are plastic clips that hold the board in place that allow the board to loose connection: try reseating the inverter boards then doing a lamp error reset. Hope this helps

[birdboy385]

Re: Sharp LC-52D85U Won't turn on

Sweet I'll give that a try and let you know thank you very much

[birdboy385]

Re: Sharp LC-52D85U Won't turn on

no dice. It appears that the board's are seated normally with the screws. i can try the lamp reset but no idea how to do that. I also find it weird that there are 2 inverter boards.

[budm]

Re: Sharp LC-52D85U Won't turn on

It uses Master and Slave Inverter boards because the lamp for 52" are very long so they need to drive the lamps in push-pull mode.

[birdboy385]

Re: Sharp LC-52D85U Won't turn on

ahh ok. bt yeah, They "look" fine. don't see any blown devices or anything. and the boards appear to be seated properly

[nicholas1110]

Re: Sharp LC-52D85U Won't turn on

Did you remove the inverter boards and reinstall them? There should be screws on one side of the board and clips on the other side. The service manual had the instructions on the lamp error reset after you reseat the boards

[birdboy385]

Re: Sharp LC-52D85U Won't turn on

gotcha, no i didn't i'll go attempt that and il check in the manual that budm found for me.

[birdboy385]

Re: Sharp LC-52D85U Won't turn on

wow this is weird design i was wondering why at first reseating would've made any difference but now i can see why it's necessary and i found the instructions on resetting

[birdboy385]

Re: Sharp LC-52D85U Won't turn on

ok so i reseated the boards, then i performed the test for getting into the adjustment menu. i get a solid green power light and can hear the tv poweringup. the backlight is on for about half a second then goes out. shortly after the power light goes back to repeated green blinking. At this point i'm assuming this means one of the inverter boards is bad or if i'm really unlucky one of the lights themselves. what would be the next step? i feel like trying to measure voltages with this won't be easy with this weird diagnostic setup.

[birdboy385]

Re: Sharp LC-52D85U Won't turn on

Normally i would check voltages going from the power supply ot the inverter but when it's stuck in diagnostic mode i doubt i'll get accurate results. anyone else have any thoughts?

[birdboy385]

Re: Sharp LC-52D85U Won't turn on

It's beyond help isn't it lol :P

[birdboy385]

Re: Sharp LC-52D85U Won't turn on

there was a simillar tv a sharp lc-32 where they had the same issue but overwrote a capacitor which controlled the diagnostics. which seemd to temporarily fix the problem. i doubt the power supply in mine is the same as the one i found. anyone know anything about that?

[f67bird]

Re: Sharp LC-52D85U Won't turn on

I would probably carefully take the panel apart and have a look at the lamps as they light. Sharps and Sanyos of that vintage had ccfl lamp problems.

[budm]

Re: Sharp LC-52D85U Won't turn on

Can we see the pictures of the whole backside of the TV so we can see all the boards?