Phillips 50PFP5332d No video or backlight

[norcalx360repair]

Hey guys. My first post here. I saw there was one related post but wasn't exactly the same problem. I am new to the tv repair scene first off. I do bga rework and other repairs on game consoles and laptops mostly. I don't have an esr cap tester or anything like that yet either.

Anyways, I'm having more and more requests for tv repair. Have a customer now with a phillips 50pfp5332d. The blue light stays solid and you can hear sound but nothing else. Also noticed an extra 'click' when you turn it on. So instead of hearing click and its on, it goes click then clicks again. Just trying to explain best I can here.

I know with lcd tv's you can shine a bright light and actually see picture if its just the backlight. Have no idea on plasma's though. I shined a light all over this one and couldn't see anything thats for sure.

I guess I could open it up and order every cap that looks like its bulged and/or leaking. I'm also looking for the service manual for this model. I'll buy it too no problem. Thanks alot guys.

[rayrod81]

Re: Phillips 50PFP5332d No video or backlight

These are notorious for the Y-main and buffers failing. Check the Mosfets on both the Y-Main and X-main boards for shorts. It is mainly the the Y-main that fails but it is possible the X-main or the Power supply has a problem. By posting pictures of the back of the TV and the boards we can help you further. Use the 'Manage Attachments' button to post pictures.

[rmoody]

Re: Phillips 50PFP5332d No video or backlight

First things first, check the obvious. If you have a fluke meter check the voltage coming out of the power supply to the ysus and xsus. These boards are on the left and right side of the tv. The power board should be labeled va and vs. Check these and see what your getting if anything. Also another simple check would be to check all the fuses on the power and sus boards.

[norcalx360repair]

Re: Phillips 50PFP5332d No video or backlight

Thanks guys. I'm opening her up tomorrow and will check these and post pictures. Thanks for the quick help!

EDIT:Sorry.. Noob status. To check for shorts in mosfets I just check for continuity from drain to gate correct?

[norcalx360repair]

Re: Phillips 50PFP5332d No video or backlight

Cracked it open... Mosfets checked out ok if I tested them right. There wasn't even one bulged/leaking cap anywhere. I found va and it tested at 5.1v so thats on point. Couldn't find vs...

While looking at the back, I know there's x and y boards on either side. Not sure which is on the left(x maybe?). I found a blown fuse on that board. Getting a fuse holder and matching spec fuse and installing it. Would be amazed if that works.

I took some pics but will upload them later after I install the new fuse. Thanks for your help so far guys! I appreciate it!

[tom66]

Re: Phillips 50PFP5332d No video or backlight

Thanks guys. I'm opening her up tomorrow and will check these and post pictures. Thanks for the quick help!

EDIT:Sorry.. Noob status. To check for shorts in mosfets I just check for continuity from drain to gate correct?

Drain to source.

Test:
- use the diode test mode on your multimeter to apply a voltage to the gate-source (this is usually around 2V open circuit and will turn on many mosfets.)
- test drain-source: you should get ~0 ohms
- reverse the leads on your meter to apply -2V to gate
- test drain-source: you should get infinite

In many cases, it is sufficient to simply test drain to source without applying a gate voltage and only a further test needs to be done to double check the fet is truly fried.

A failed MOSFET will also sometimes get a drain to gate short but not always.

[norcalx360repair]

Re: Phillips 50PFP5332d No video or backlight

Here's the meter I have. I'm really sorry I'm such a noob here but really its helping me to understand. I've never had to test mosfets in the electronics I work on, as the problems are 95% bga failure.

here's the meter I'm working with:





EDIT:Just tried to test some mosfets on an xbox board. I got the same reading by applying gate votage or without. Maybe this DMM is a POS? Not enough test voltage or something? I got infinite either way. Thanks for your patience guys. I'm seriously wanting to get into tv repair as well. I'll buy all the proper equipment and read for 1,000,000 hours etc. THANKS for the tips.

[tom66]

Re: Phillips 50PFP5332d No video or backlight

Here's the meter I have. I'm really sorry I'm such a noob here but really its helping me to understand. I've never had to test mosfets in the electronics I work on, as the problems are 95% bga failure.

here's the meter I'm working with:





EDIT:Just tried to test some mosfets on an xbox board. I got the same reading by applying gate votage or without. Maybe this DMM is a POS? Not enough test voltage or something? I got infinite either way. Thanks for your patience guys. I'm seriously wanting to get into tv repair as well. I'll buy all the proper equipment and read for 1,000,000 hours etc. THANKS for the tips.

Infinite is good - short circuit is how most MOSFETs fail. Do you have anything on your meter that looks like a diode?

[rayrod81]

Re: Phillips 50PFP5332d No video or backlight

Looking at it from the back the y-main is on the left and the x-main is on the right. If the fuse is blown on the Y-main then something has failed on that board. The buffers may or may not be good but if you put a fuse in and the Y-main is bad it could take the buffers with it and you will have to replace all 3 boards. You might get lucky but you should be completely sure that there aren't any bad components on the board before you put power to it.

[rmoody]

Re: Phillips 50PFP5332d No video or backlight

Yep, if it's blowing the slow blow fuse on the ysus it's probably the hybrid IC and will need to be replaced or sent to someone for service. Coppel tv is pretty reputable on this procedure.

[rayrod81]

Re: Phillips 50PFP5332d No video or backlight

This model is built with mosfets and transistors, no IPMs. It should be repairable but it could be less expensive just to replace the board. The common failures on this board are 10 mosfets on the heatsink nearest the buffers and 1 smd mosfet.

[norcalx360repair]

Re: Phillips 50PFP5332d No video or backlight

Oh, I'm glad you guys said that. I'll just check the price on the whole board for now. I didn't even see 10 mosfets on it. I took some pictures but they are crappy really. Didn't even get the model number on the board itself.

I do have the diode setting on my meter. It just looks like an arrow with a line, right? I'm hoping thats it anyways lol. Its the same as continuity on this meter. Thanks again guys.

[norcalx360repair]

Re: Phillips 50PFP5332d No video or backlight

I found the service manual for a model that has the same parts in it. Its the hp5054. Its pretty sweet. Will update with results.

EDIT:I've been reading for a few minutes and coppel does y sus repairs on ebay. Not sure how much the buffers are but I see they only have warranty on this y sus repair if you either send it in with the buffers OR buy the buffers from them or someone they trust. Very understandable too.

I was really hoping to actually fix whatever is wrong with it VS just getting someone else to do it but I'm a complete noob lol. We'll see what happens. Since they have to fix the buffers anyways too, I'll just go for the fuse screw it. I have about 20 hours of other work to do and this is pro bono work right here lol. They'll probably just buy a new one anyways.

I think thats the problem with just swapping boards etc. Its gets too expensive and its not worth it. The experience is definitely good though.

[norcalx360repair]

Re: Phillips 50PFP5332d No video or backlight

Well, they wanted me to try on the fuse and it didn't work of course. That would be too easy. I'm sending off the ysus and buffers then..

[rmoody]

Re: Phillips 50PFP5332d No video or backlight

here's the service manual for the tv. You have to go by the chassis number on the panel.

[norcalx360repair]

Re: Phillips 50PFP5332d No video or backlight

Thanks.