Philips 47PFL7403D/10

[vazaki]

Hi there to all!!

New to forum, first post but watching it several months silenlty.

I need your advice:

Philips 47PFL7403D/10
power supplyQ PLHC-T801A (UD)

No response while connected to wall plug.

I figured out that R5 is burnt. I have changed it with a new one and now when plugged in a relay is clicking all the time.
No led blinking.
After a minute the R5 is broke down again and everything dead.
All caps esr measured and they are very good.

Any advice for this issues?

Is it truly the problem from the PSU or maybe the mainboard?

Thanks a lot
Nodas

[tvtimmy]

Re: Philips 47PFL7403D/10

You need to change u101. It is a 7 leg ic chip that is through hole soldered in.
Put a new 120 ohm resistor in r5 and put the correct fuse back in around that r5. Also, check the solder connections under the power board, the ones under the transformers tend to burn and start on fire. Touch up all the through hole componnets with fresh solder.

[R_J]

Re: Philips 47PFL7403D/10

opps, wrong power supply

[tvtimmy]

Re: Philips 47PFL7403D/10

Post some pics of the power board. Take one of u101, you may see a hole in the side of it, or a blown off leg.

[vazaki]

Re: Philips 47PFL7403D/10

Timmy thank you very much for your response and help.

I have changed already:
> U101
> D101A,D101B,D101C,D101D
> PC201,PC101,PC102

The result was that relay clicking and after a little the R5 burnt again. The fuse I have changed once did not blow again.

The solder joins are in very good condition.

Also I have tested D106A and it seems open. the diode writes T2d 83 on it.
do you jnow anything about this?

[dick_barton]

Re: Philips 47PFL7403D/10

What is the mark on top of the 8 pin IC. Picture too small to read component names.

[ducky29]

Re: Philips 47PFL7403D/10

Check zd 101 and zd 103 on the back of the power supply

[vazaki]

Re: Philips 47PFL7403D/10

What is the mark on top of the 8 pin IC. Picture too small to read component names.

Oh man!!
You are tottaly right!
After the replacement U101 is broke down again. The spot show that ic is fried.

[vazaki]

Re: Philips 47PFL7403D/10

Check zd 101 and zd 103 on the back of the power supply

Zd101 tested with multimeter seems fine but
Zd103 shows the same value both sides with multimeter but I see that it is in parallel with an smd capacitor.

Do I have to desolder it to check it again?
Should I check with external voltage?
Do you know the value of the zener diode?

[dick_barton]

Re: Philips 47PFL7403D/10

Oh man!!
You are tottaly right!
After the replacement U101 is broke down again. The spot show that ic is fried.

That's the beauty of posting photo's.

[ducky29]

Re: Philips 47PFL7403D/10

zd101 tested with multimeter seems fine but
zd103 shows the same value both sides with multimeter but i see that it is in parallel with an smd capacitor.

Do i have to desolder it to check it again?
Should i check with external voltage?
Do you know the value of the zener diode?

zd101 5.6
zd103 18

[vazaki]

Re: Philips 47PFL7403D/10

Thank you very much!!

I desolder U101 and measured again ZD101 & ZD103 with multimeter and they seem fine. Do I have to desolder them and check them again?

[ducky29]

Re: Philips 47PFL7403D/10

No its fine

[vazaki]

Re: Philips 47PFL7403D/10

Thanks

Any other suggestions?

[dskall]

Re: Philips 47PFL7403D/10

What is the part # of U101

[Davi.p]

Re: Philips 47PFL7403D/10

if you want to be helped, you can post very clear pictures of te board or even the faulty portion, both sides, with traces well distinguishable, and put marks on them to show parts changed and parts found blown.. one can have no wants to find and download schematic..

[tvtimmy]

Re: Philips 47PFL7403D/10

U101 is FSQ510. Lots of them on ebay.

[dskall]

Re: Philips 47PFL7403D/10

So it looks like output of U101 bad. What is causing failure? Transformer shorted?
https://cdn.badcaps-static.com/pdfs/...f3dad871c4.pdf

[vazaki]

Re: Philips 47PFL7403D/10

Here are the photos!
The parts that have been replaced:
> R5
> D101A
> D101B
> D101C
> D101D
> PC101, 102, 201

Also I need your help about T2D 83 diode. I measure it with the classic way but it seems open. Is it a special type of diode?

[dick_barton]

Re: Philips 47PFL7403D/10

R5 does not look good. Best that you check its resistance.