Sharp aquos LC-40LE810E

[marksik]

Re: Sharp aquos LC-40LE810E

Just measured voltage at pin 12 of that 12-pin connector and got 3,5V. Also measured pin 1 of PNL-12V connector and got 12 volts.

But it all drops in 5-6 seconds, so may be KIA is the real problem...

[marksik]

Re: Sharp aquos LC-40LE810E

I ordered KIA378R12PI from eBay. It will come in 2-3 weeks and I will inform about results.

Damn, I have been waiting for optos about 1 month and now I have to wait another month

[marksik]

Re: Sharp aquos LC-40LE810E

Aussie: don't make confusion, you have a different issue, open up your own discussion.
Marksik: to make long story short, no need to change any resistors, put back the original ones, and change the optocoupler, if the AC_DET works again try the tv, if it work no more inspect/change the KIA voltage regulator..

Davi.p, thanks for your answer. I changed all optos (4 pics) and nothing changed. Situation remaining as described above. Can you please point on KIA voltage regulator - where I can find it on the board. Did you mean 4-legs element (kia378r12) which is situated under the metal shield?

Thank you

[Davi.p]

Re: Sharp aquos LC-40LE810E

Aussie: don't make confusion, you have a different issue, open up your own discussion.
Marksik: to make long story short, no need to change any resistors, put back the original ones, and change the optocoupler, if the AC_DET works again try the tv, if it work no more inspect/change the KIA voltage regulator..

[Aussie_Matt]

Re: Sharp aquos LC-40LE810E

I've just brushed the dust off: It appears C7813 s cracked.

[Aussie_Matt]

Re: Sharp aquos LC-40LE810E

Hi guys I have a sharp LC-40LE820X, and the main power board is a DPS-126CP B.

I can display pictures from a usb for hours on end.

When on TV function, after a period of time (20 minutes or so) the picture becomes choppy, then appears to turn off: When I try to turn it on it then has a warning similar to "service has been changed, execute auto install".

I suspect a power supply issue: Does this sound right?

[Aussie_Matt]

Re: Sharp aquos LC-40LE810E

Hi guys, I have a Sharp LC

[marksik]

Re: Sharp aquos LC-40LE810E

Update. I tried Vol - CH + Power trick. Screen backlight turned on but no image. Just brigth screen. Red LED on motherboard blinking with 5 sec period. When I turn the TV off with remote, it turns off, then U can turn it on again (without image).

But if I use its hardware button and turn it off, it doesnt turns on again, I have to use Vol - CH + Power trick again.

And the same happens if I put back cable #9 without resistor. I can turn on the backlight but with no image.

[marksik]

Re: Sharp aquos LC-40LE810E

Update. I tried Vol - CH + Power trick. Screen backlight turned on but no image. Just brigth screen. Red LED on motherboard blinking with 5 sec period. When I turn the TV off with remote, it turns off, then U can turn it on again (without image).

But if I use its hardware button and turn it off, it doesnt turns on again, I have to use Vol - CH + Power trick again.

[marksik]

Re: Sharp aquos LC-40LE810E

HI guys.

I have the same problem as topic starter.

I already replaced resistor r7019 to new one (33k), also used 560 ohm resistor for this trick with 9-11 cables. I think that after this trick with cables (but before 7019 resistor replacement) I saw that screen turned on for couple of seconds.

But it was only once. After resistor replacement TV still doesn't work. When I turn it on, for 7 seconds its front V-light turns on without flashing. Also I see that red LED on motherboard turns on after 5 seconds. And then red LED turns off and V-light starts blinking (2 short blinks then nothing, then again 2 short blinks and again).

Then, if I press Power button on its remote for 2 second, V-light turns off then turns on without flashing, and LED on motherboard turns on and we have the same story as I described above.

Help me please.

P.S. I didn't replace optos, just bought them at AliExpress.

[Jstone86]

Re: Sharp aquos LC-40LE810E

Next is to keep the DCV meter on the PL connector, remove the ribbon cables between the LCD panel and T-CON to see if the PL connector will jump up to 12VDC or not when TV is turned on.
BTW, did you do the test with the dummy load?

After I removed the ribbon cable between lcd and tcon board I got same voltage 0.67v.i couldn't do the dummy test cuz I was waiting for the KIA378R12PI ic I ordered from online. Even then am confused on how to do the dummy test cuz I am a novice so if you can please upload any pics /vdeo or link to any post here with instructions on how to do the dummy test. Thanks

[budm]

Re: Sharp aquos LC-40LE810E

Next is to keep the DCV meter on the PL connector, remove the ribbon cables between the LCD panel and T-CON to see if the PL connector will jump up to 12VDC or not when TV is turned on.
BTW, did you do the test with the dummy load?

[Jstone86]

Re: Sharp aquos LC-40LE810E

After theKIA378R12PI (Q7909) arrived, I changed it and as usual TV dosent turn on. Previously I got 2v PL pin 1 and 2 when I turn on the TV but now get 0.67v so memu touch key buttons don't respond only TV remote also the led light blink 2-2 without stopping hmm. If I disconnected the Pl connector I get 12volts on PNL pin 1ansd 2

[Davi.p]

Re: Sharp aquos LC-40LE810E

I think this test is facoltative, i guess surely your KIA is bad, wait the piece and try it.. bye.

[Jstone86]

Re: Sharp aquos LC-40LE810E

OK, next test will be with dummy load, you can simulate 1A load by using 12 Ohms 10W resistor to see if it can handle 1A load or not.
If you are going to use the lamp, you need to check its cold resistance first since cold resistance will be about 15 times lower than the hot resistance.

I think i can get 12R 10W resistor from the local electronic shop here but i have also ordered KIA378R12PI from aliexpress which delivery is approximately 2 weeks.by the way can you please show me how i can stimulate or test with the 12R 10W resistor.pictures wud be better .thanks

[Davi.p]

Re: Sharp aquos LC-40LE810E

Hi Budm, warning: my test with external supply to tcon was faulty due to a defective crocodile test cable used, swapped it with a good one the tv is perfectly working so the problem is merely the only KIA chip that is faulty, BYE BYE to ALL.

[budm]

Re: Sharp aquos LC-40LE810E

OK, next test will be with dummy load, you can simulate 1A load by using 12 Ohms 10W resistor to see if it can handle 1A load or not.
If you are going to use the lamp, you need to check its cold resistance first since cold resistance will be about 15 times lower than the hot resistance.

[Davi.p]

Re: Sharp aquos LC-40LE810E

You have to put a resistor or a 12v Lamp as load to the PL output so you can judge better if KIA is good or not. If it stays on then the tcon has problems.

[Jstone86]

Re: Sharp aquos LC-40LE810E

Disconnect the PL connector on the T-CON board then put the on the PNL12V pin on the power supply board then turn on the TV to see if the output will jump up to 12V or not, if not then more likely to be bad KIA.

I indeed get 12v when I disconnected the Pl connector. But only 2v flows in when I connected back the Pl. So that means my KIA378R12PI is OK right? What do u suspect the problem is

[budm]

Re: Sharp aquos LC-40LE810E

Disconnect the PL connector on the T-CON board then put the on the PNL12V pin on the power supply board then turn on the TV to see if the output will jump up to 12V or not, if not then more likely to be bad KIA.