LG 42PC1RR-ZL y sus problem

[luiznunes]

Re: LG 42PC1RR-ZL y sus problem

anyone knows what is the IC13 KA5H080R on the circuit ?

http://images3.hiboox.com/images/390...fa988718f8.bmp

[Th3_uN1Qu3]

Re: LG 42PC1RR-ZL y sus problem

Someone was hungry and the 3 was the only thing he could find to eat. Here you go. It's a power supply controller with built in power mosfet.

[luiznunes]

Re: LG 42PC1RR-ZL y sus problem

since I don't have the exact schematics of this board ( the PS101 ), how can I discover what is wrong with it?

[PlainBill]

Re: LG 42PC1RR-ZL y sus problem

since I don't have the exact schematics of this board ( the PS101 ), how can I discover what is wrong with it?

You start by taking pictures of the power supply - one of the top and one of the bottom - and posting them HERE using 'Manage Attachments'. I've had enough problems with '.jpgs' posted offsite that wouldn't open or contained something extra. Don't post them inline.

PlainBill

[luiznunes]

Re: LG 42PC1RR-ZL y sus problem

you mean the power supply board, or the PS101 of the Ysus board pictures?

[PlainBill]

Re: LG 42PC1RR-ZL y sus problem

you mean the power supply board, or the PS101 of the Ysus board pictures?

Sorry, it was early and I wasn't paying attention. Yes, pictures of the top and bottom side of the PS101 would be helpful. It may be necessary to use wires to extend PS101 above the board so you can make measurements.

Actually, let me make a suggestion. With PS101 still in place take pictures of the top and bottom showing as much as possible. I have a similar board here; if they match it will make things much easier. If they don't, well, it's little time lost.

Or you could shotgun it by replacing the electrolytic caps.

PlainBill

[luiznunes]

Re: LG 42PC1RR-ZL y sus problem

hey, you don't have to appologize!

I am the one who's need help!

here it is the pictures. if you can see what you want, please tell me and I take more.

[PlainBill]

Re: LG 42PC1RR-ZL y sus problem

hey, you don't have to appologize!

I am the one who's need help!

here it is the pictures. if you can see what you want, please tell me and I take more.

It's built on the same board, but there are a few dash number (version) differences, almost certainly due to a different output voltage. Borrowing on other reports, I'd replace C25 - it's the smallest electrolytic cap - 100 uF, 35 volts on mine. If that is leaky it could affect the output voltage.

PlainBill

[luiznunes]

Re: LG 42PC1RR-ZL y sus problem

to replace it, I need to un-solder the PS101 from the Ysus, right? because I don't have much access to put an iron there..

[luiznunes]

Re: LG 42PC1RR-ZL y sus problem

don't you think that, because of the very slow drop of voltage until it reaches the correct 200V is due to a faulty resistor?

[PlainBill]

Re: LG 42PC1RR-ZL y sus problem

don't you think that, because of the very slow drop of voltage until it reaches the correct 200V is due to a faulty resistor?

Yes, you will have to remove PS101 from the main board.

While it is possible, it's unlikely. Others have reported problems with these units and found it was due to a bad cap.

And it turns out my memory was faulty. Here's the post. Perhaps there are enough clues to help you.

PlainBill

[luiznunes]

Re: LG 42PC1RR-ZL y sus problem

It's built on the same board, but there are a few dash number (version) differences, almost certainly due to a different output voltage. Borrowing on other reports, I'd replace C25 - it's the smallest electrolytic cap - 100 uF, 35 volts on mine. If that is leaky it could affect the output voltage.

PlainBill

already replaced. problem remains the same...

[PlainBill]

Re: LG 42PC1RR-ZL y sus problem

already replaced. problem remains the same...

Off to do some yard work and cogitate on the problem. Bump the thread if I don't update by Monday evening.

PlainBill

[luiznunes]

Re: LG 42PC1RR-ZL y sus problem

ok, thanks.

[luiznunes]

Re: LG 42PC1RR-ZL y sus problem

I measure the output of the transformer and is a stable 210V

[PlainBill]

Re: LG 42PC1RR-ZL y sus problem

I measure the output of the transformer and is a stable 210V

OK, now you have me thoroughly confused. Is the output of PS101 a stable 200 (or 210) volts?

PlainBill

[luiznunes]

Re: LG 42PC1RR-ZL y sus problem

OK, now you have me thoroughly confused. Is the output of PS101 a stable 200 (or 210) volts?

PlainBill

more or less stable. Why?

[luiznunes]

Re: LG 42PC1RR-ZL y sus problem

OK, now you have me thoroughly confused. Is the output of PS101 a stable 200 (or 210) volts?

PlainBill

It shouldn't be stable or shouldn't be around 200?
I can check again.

Isn't the PS101 the same as the PS102? Same component and values except the transformer?

[PlainBill]

Re: LG 42PC1RR-ZL y sus problem

It shouldn't be stable or shouldn't be around 200?
I can check again.

Isn't the PS101 the same as the PS102? Same component and values except the transformer?

Let's see if we are on the same page here. In an early post you indicated Vy was too high (250V) and the picture was bad when the TV was turned on. After a few minutes Vy would drop to the proper value and the picture became good. Or am I totally confused?

After changing C25 is Vy stable and is the picture good when the TV first comes up??

PlainBill

[luiznunes]

Re: LG 42PC1RR-ZL y sus problem

Let's see if we are on the same page here. In an early post you indicated Vy was too high (250V) and the picture was bad when the TV was turned on. After a few minutes Vy would drop to the proper value and the picture became good. Or am I totally confused?

After changing C25 is Vy stable and is the picture good when the TV first comes up??

PlainBill

Ok, my bad. I must measured the PS102 that time. sorry.
Here I enclose a PDF file showing the evolution of Vy and the output of the transfomer. If you want I can send the excel file with the data.
I was asking about the PS101 and PS102 having the same schematics, so I may compare some values between them.