Sharp aquos LC-40LE810E

[Jstone86]

Re: Sharp aquos LC-40LE810E

So budm just to clarify for my TV, I need to CHANGE the KIA378R12PI??

[budm]

Re: Sharp aquos LC-40LE810E

HI Budm, sorry, you are meaning the KIA is a common problem for theese tvs? I have ordered the part from Aliexpress. We will see between 1/2 months maybe.

Example:
https://www.badcaps.net/forum/showth...ht=KIA378R12PI
https://www.badcaps.net/forum/showth...ht=KIA378R12PI

[Jstone86]

Re: Sharp aquos LC-40LE810E

Too much pictures from me, e-ehm... that seems only a pencil mark..

Hehehe just wants to make sure that I ruled everything out

[Davi.p]

Re: Sharp aquos LC-40LE810E

Too much pictures from me, e-ehm... that seems only a pencil mark..

[Jstone86]

Re: Sharp aquos LC-40LE810E

I noticed something today, if 8 removed the tcon connector pin power from psu board I get 12volts on PNL pin 1 & 2 2 which immediately drops to 0.but when I connected the tcon I get 2 volts on pnl pin 1 & 2 and drop as usual. By the way the I think there might be some problems with the tcon cuz I see some black mark on the tcon Pl female comector. Here is ten attach pics

[Davi.p]

Re: Sharp aquos LC-40LE810E

Damn! Some sad doubts comes... I have supplied externally 12v to the tcon leaving the PSU tcon supply connector disconnected, before i switch on the tv i switch on the ext. PSU, the voltage falls to the same 7V, when i switch on the tv suddenly tcon voltage become 12v but after some secs tv goes in protection with the same 2 flashes and tcon voltage falls to the 7V. I have done researches on tcon, none of the power semicon tests in short with tester current in, also tested one internal mosfet of a pmic. I'm sad...

[Davi.p]

Re: Sharp aquos LC-40LE810E

HI Budm, sorry, you are meaning the KIA is a common problem for theese tvs? I have ordered the part from Aliexpress. We will see between 1/2 months maybe.

[budm]

Re: Sharp aquos LC-40LE810E

'KIA378R12PI' That is the common failure Switched 12V LDO regulator IC.

[Davi.p]

Re: Sharp aquos LC-40LE810E

The 13,2V output supply rail is regulated by the fixed linear regulator KIA378R12PI (Q7909) that outputs 12v normally, with an enable pin, as the d.sheet says the eanble pin (Vc) activates output when is >=2v, mine is 3v from the PNL_POW signal so i think the KIA doesn't work well.

[Davi.p]

Re: Sharp aquos LC-40LE810E

Hi, i have the same TV with same problems as Jstone, apart the fact that i have not put any new resistor, i have changed the PC7703 opto with a good one and now i have good AC-DET signal, then i've changed the rest of the 3 opto with no changement, i have from seconds by the power-on and for some seconds a tension of appr. 7V on PNL-12V then it decreases to 0 slowly. Now i will study the PANEL SUPPLY that is probably a separate supply stage.

[Jstone86]

Re: Sharp aquos LC-40LE810E

Since you do have 3.25V PNL-POW control signal, so do you get 12V at the PNL-12V connector pin?

Finally I was able to located PNL-12V. I got 2 volts when I Power on the TV and it immediately drop to 0

[rievax_60]

Re: Sharp aquos LC-40LE810E

PNL-12V should be pin 1 of PL connector.

[Jstone86]

Re: Sharp aquos LC-40LE810E

Pins 1 and 2 of PC7703 are on the live side. Leave them alone for now.
The schematic for the power supply can be found here,
If AC-DET is high while ever PS-ON is high, it means that the AC-DET is working properly.

So which way forward? At the moment am not sure about the next step to take maybe Budm can throw more light in regards to 12V PNL connector pin which I can't located on the motherboard except PL on the inverter board. Can guy help me located PNL-12V connector pin since guy have same TV model

[rievax_60]

Re: Sharp aquos LC-40LE810E

Pins 1 and 2 of PC7703 are on the live side. Leave them alone for now.
The schematic for the power supply can be found here,
If AC-DET is high while ever PS-ON is high, it means that the AC-DET is working properly.

[Jstone86]

Re: Sharp aquos LC-40LE810E

I am also noticed something and don't know if it's unusual with regards to PC7703
Both PIN 1 and 2, I get 2 volts which stays steady immediately I turn on the power of the TV but keep on fluctuating but never drops down beyond 2volts. It stays at 2volts but keep on fluctuating.
For PIN 3 and 4,immediately I turn on the power of the TV, I get 4 volts and it immediately back to 0 volts when the red light on the motherboard goes off.
I will upload pic of the red light on the motherboard for reference

[Jstone86]

Re: Sharp aquos LC-40LE810E

Please upload good clear pictures of YOUR board.

Sorry for the late response. I have been having troubles in uploading the pictures here

[budm]

Re: Sharp aquos LC-40LE810E

Sorry I am novice so a little confused where can I please locate PNL connector pin??

Please upload good clear pictures of YOUR board.

[Jstone86]

Re: Sharp aquos LC-40LE810E

Since you do have 3.25V PNL-POW control signal, so do you get 12V at the PNL-12V connector pin?

Sorry I am novice so a little confused where can I please locate PNL connector pin??

[Jstone86]

Re: Sharp aquos LC-40LE810E

Those voltage readings show that the AC-DET is working properly.
There must be something else wrong, Does the voltage on pin 1 disappear after 7 seconds also?

No sir. The voltage on pin 1 of pc7702 stays on and dosnet dissaper. I measure about 2volts

[budm]

Re: Sharp aquos LC-40LE810E

Since you do have 3.25V PNL-POW control signal, so do you get 12V at the PNL-12V connector pin?