Philips 42pfl3606 efforts on repairing the psu

[senndogg]

Hello. Its been almost a month waiting for several pieces to come from ebay, several reworks made, and now i am at the point of giving up. But before i do, i need your honest opinions.
This LCD Tv was stricken by a lightning and was totally dead when came.
Main fuse blown.
Checked for short in the main capacitor, OK. replaced fuse and blown again. Rectifier faulty. Changed it and the fuse.
TV led was lit. 5V standby was ok.
PS_ON 3.3V but no 12/24V.
After many measurements decided to order the IC controller of this rail.
Replaced the IC and the mosfet. 12 and 24V now are OK.
TV working without backlight. Examined the 24pin IC of the backlight and found many shorts. Found also some traces of possible arc-ing between smd components (last pic).
I am ready to order this IC, but now i am very pessimistic.
I need some opinions.
Thank you.

[senndogg]

Re: Philips 42pfl3606 efforts on repairing the psu

UPDATE!
happy to tell that: took the backlight IC from a similar lcd-faulty philips in my workshop and now it is working !!!
Thank you for the time!

[selldoor]

Re: Philips 42pfl3606 efforts on repairing the psu

Good fix - your too quick I looked at your post briefly but was tired and thought Ill look at that tomorrow and here I am - too late.
Did you resolder those joints as well?

[senndogg]

Re: Philips 42pfl3606 efforts on repairing the psu

yes, i restored the cut traces, resoldered and cleaned everything. Now its been nearly 2 hours the Tv is working well.

[Ltank]

Re: Philips 42pfl3606 efforts on repairing the psu

What was the IC# and actual part number for others to reference to?
Thanks

[senndogg]

Re: Philips 42pfl3606 efforts on repairing the psu

The backlight IC801 is a UBA2071AT from NXP.
The 12/24V controller is a NCP1271A from OnSemi.
The 12/24V original mosfet which i dont remember, was changed with a Toshiba 2SK2797.
The last 2 are bought from a well known HongKong supplier and came in 8 days.
Anyway this scenario was provoked by a lightning, i have barely seen 24pin BL ships failing.

[bangy]

Re: Philips 42pfl3606 efforts on repairing the psu

Hi,i got almost same problem but i got only +5v everything seems good ,caps ok.
No 12v and 24v. Tv works fine 2,3 days and after that dont work few days...
Anybody can help me or advice

[dick_barton]

Re: Philips 42pfl3606 efforts on repairing the psu

Is this the service manual


https://cdn.badcaps-static.com/pdfs/...e8f6774242.pdf

If your power supply matches the one shown in section 10.2 - PSU Thriller 42" - then disconnect the power supply from the main board and short pins 10 & 11 on CN903 and check for 24V and 12V using your multimeter.