Sharp LC-52D85U Won't turn on

[birdboy385]

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

Slave board
775
778
780
778
785
783
786
785
785
785

[birdboy385]

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

The other board's were all around 770

[dick_barton]

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

My apology for the confusion Birdboy385. I should have been clearer with the request. I know the image is small but the intention was for you to check the resistance of each transformer to see if it matched the value as shown in the picture between those pins.

[birdboy385]

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

no problem lol. Well it would appear that none of them are reading the 1.3K OHms. Idk what them mostly reading around 775 means. Then there is the one that gives off no reading.

[dick_barton]

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

It does look as though one of them is faulty so hopefully you have found the fault.

[birdboy385]

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

I wasn't sure if the others reading only around 775 instead of around 1.3K is a problem or if that's not as much an issue. Basically my question is are they all relatively bad at 775 or just the one i found.

[dick_barton]

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

The picture was taken off the internet so I'm not certain how accurate the 1.3K is for the transformer.
However since all the transformers measurements were very similar except for one which you said gave no reading then I would suspect that it is only that one that needs to be replaced.

[bangjay]

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

I had problems with Sharp LCD TV type LC-32L50M, current conditions, if I turn it on the LED indicator green and red flashing alternately several times, after that only a red LED that flashes 5x, when the red flashing, all the buttons do not work.

according to my analysis, this tv failed to start because of a protected, I've tried to enter service mode with Vol - and TV / Video and plug the power, but the tv screen was still dark, there is no display anything on the screen. and LED indicators remain blinking as described above.
I've done a test voltage, everything is normal,

1. BU1.8V ok
2. BU2.5V oK
3. BU3.3V OK
4. BU5V OK
5. BU12V OK
6. DC 14V / 24V OK


anyone can help me? whether about the problem?

[budm]

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

You should start a new thread with make and model and picture so it will not confuse other people.

[bangjay]

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

You should start a new thread with make and model and picture so it will not confuse other people.

thank you,

[birdboy385]

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

Ok so update. I replaced the transformer and the tv seemed to be ok. I held the power button the light went orange. I turned it on and it came on like normal. Then i went to factory reset it and i'm getting a new error code that i can't bypass. It's alternating between blinking power and power + opc alternatively. I'm going to look in the manual to see if i can lock it down. Anyone know off hand what it might be?

[birdboy385]

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

It's difficult to read the error code with he manual but I can say that it alternates between blinking 1 power and 1 power + opc. Trying the Channel down / Volume down + input reset doesn't work. If i unplug the tv and plug it back in it blinks power infinitely like it did before.

[birdboy385]

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

ok new update. I let the tv sit for awhile unplugged then went back to it a few hours later. I managed to get it completely reset andf it seems to be working fine. Not sure why it was flashing those codes before but it seems fine now. I will keep you guys updated.

[dick_barton]

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

Sound like good news.

[birdboy385]

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

Thus far I've encountered no issues. I'd like to take this opportunity to thank everyone who contributed to help me not just for this tv but for everyone on these forums who are there to help. Is there a way to donate to the cause? Once i get this tv sold i'd like to make a contribution.

[dick_barton]

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

I think the best contribution to the Forum is the offer of help to others as and when you can although there is a Donate button at the bottom of the page.

[nobbnobb1]

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

Sorry to bump an old thread but I am also trying to diagnose a no picture/start up issue with this TV. The green Power LED just has a continuous blink. Similar to what was mentioned on the last page, when I try to enter the adjustment mode (holding volume down & input buttons while applying power), there is a brief blue screen that lights up (backlight powers up briefly), then it goes back to blinking with the power supply seemingly shut off.

I am reviewing the service manual () and there appears to not be any references to what the voltages on the power supply board should be? The PCB does not appear to label all the voltages clearly.

Any thoughts?

EDIT: I was able to force the TV to turn on. Inverter seems to attempt to strike the backlight briefly but then it goes off. While power button stays lit, I tested various points on the power supply and got a range from 3.3, 5, and 12V. Once again, things aren't labelled properly on the PCB so I'm having trouble telling what the voltages should be.

[budm]

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

Did you read post 36 and later and check the transformer winding resistance?

[nobbnobb1]

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

Did you read post 36 and later and check the transformer winding resistance?

Doh! Turns out I was measuring the wrongs pins. The arrows in the image on post #36 should actually be reversed. I think I found the bad transformer now (just one on the master board)...will try to replace this part and see what happens.

Did further testing and I'm fairly confident the power supply board is good, even if I couldn't find reference material on the proper voltages.

I also tried the hairdryer trick on the capacitors on the inverter board, no change.

Will report back when I get this transformer changed out!

EDIT: It doesn't seem I can source the transformer with part number 2874025500 anywhere. Would there be a way to lookup a compatible part? Or perhaps someone here diagnosing these boards has an extra they could sell?

[nomoresonys]

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

Something there, the first one is just a transformer, it's about as much as a whole board tho, there's a little test they included on the first one: https://www.ebay.com/sch/i.html?_fro...acat=0&_sop=15