Philips 50pfp5532d - no picture but sound

[Strike1]

Got a tv in this current state. I've read a few threads on this or similar samsung models. I've taken the back cover off and all connectors seem to be well connected. What's the next step? Check the Y sustain board?

A lot of the components are covered in dust. Is it ok to clean it up using compressed air, or is it not worth it?

[capkid]

Re: Philips 50pfp5532d - no picture but sound

Yes, I'd clean with compressed air before you start working on it. Check power supply VS and VA output voltages to see if the PSU is providing voltage to the Y-Main and X-main. Also, check the Y-main and X-main for visible physical damage and blown fuses. In these "sound, but no picture" situations, the Y-main and X-main are the usual suspects.

Provide pics if you need help locating test points.

[Strike1]

Re: Philips 50pfp5532d - no picture but sound

I've taken a picture...this is what it looks like with the back off. Which component is which?

[Strike1]

Re: Philips 50pfp5532d - no picture but sound

Okay, I've checked fuses on the left and right boards, they seem to be okay.

The centre board, which looks like the PSU seems to have a blown capacitor. I've not had much experience identifying bad caps but this one seems pretty obvious...

According to the specs it is a 10v 3300uF capacitor.

Could a single capacitor be the cause of the loss of picture?

[Strike1]

Re: Philips 50pfp5532d - no picture but sound

Here's the capacitor in question, and a second picture zoomed out to give some perspective.

[capkid]

Re: Philips 50pfp5532d - no picture but sound

Yes, that cap is blown. Is the cap next to it the same capacitance and voltage? If so, I'd change it at the same time. You may have other damage, so at least closely examine the board for burned components. A flashlight might be helpful.

Edit: Once your PSU is functioning properly, and if you still have no picture, you can further isolate the issue to a possible sustain board problem.

[Strike1]

Re: Philips 50pfp5532d - no picture but sound

Yes, that cap is blown. Is the cap next to it the same capacitance and voltage? If so, I'd change it at the same time. You may have other damage, so at least closely examine the board for burned components. A flashlight might be helpful.

The blown one is a 3300uF 10v capacitor, the other one is 25v 1500uF. Should I replace it anyway?

I've examined the power board using a light, I couldn't see any signs of damage or burning, it's a little difficult to see the MOSFETs (?) under the heat sinks.

Should I just replace the capacitors and try the tv out again?

[capkid]

Re: Philips 50pfp5532d - no picture but sound

You're probably fine just replacing the 3300V cap. What is your PSU's part number? It should begin with "LJ41" or "LJ44". There may be a recommended cap kit.

[Strike1]

Re: Philips 50pfp5532d - no picture but sound

You're probably fine just replacing the 3300V cap. What is your PSU's part number? It should begin with "LJ41" or "LJ44". There may be a recommended cap kit.

It has two:
Lj92-01513a
Lj92-01511a

First one is for 42", second is 50". I guess the same part fits both versions of the tv.

[capkid]

Re: Philips 50pfp5532d - no picture but sound

Here's a repair kit for a dead PSU issue. I wouldn't go down that road just yet, since your PSU isn't dead - just trying to identify common issues with this PSU: http://www.ebay.com/itm/tkit21-Phili...item2ec93c4b98

[Strike1]

Re: Philips 50pfp5532d - no picture but sound

Here's a repair kit for a dead PSU issue. I wouldn't go down that road just yet, since your PSU isn't dead - just trying to identify common issues with this PSU: http://www.ebay.com/itm/tkit21-Phili...item2ec93c4b98

Great. I'm heading down to my local electronics store to pick up the cap. If it doesn't work I'll probably just buy that kit, it'll save me a million trips to maplins.

Hopefully it'll work, and my mum can go back to watching corrie on a plasma instead of an ancient 24" CRT!

Thanks for the advice.

[capkid]

Re: Philips 50pfp5532d - no picture but sound

I'd go with a high quality cap: Panasonic, Nichicon, Rubycon, etc. There's lots of info on the forum about replacement caps.

[Strike1]

Re: Philips 50pfp5532d - no picture but sound

Ok, I replaced the cap but the problem remains. There's two green leds that shine, one on a board connected directly to the PCB, another on the board below it. Not sure what that means.

I checked the voltages coming out, Vs was 2.75, Vg was 14.91. Seemed lower than I would have thought.


According to a table printed on the PCB, the output rating for Vs is 200-215v, and Vg is 15v. Does that mean the PCB is fried?

[capkid]

Re: Philips 50pfp5532d - no picture but sound

It looks like your PSU is still faulty, since the VS is apparently not being produced correctly. Some of these Philips PSUs show visible signs of failure (e.g. burned components), so I'd take a flashlight and closely examine the board. Are the LEDs flashing? How many times? The one on the PSU is particularly of interest. Please post pics.

[Strike1]

Re: Philips 50pfp5532d - no picture but sound

I had a good look at the board when I took it off and cleaned it. I couldn't see any signs of damage anywhere, although the coils looked very dusty...maybe there's a short in them?

The green LED is on the board bottom right of the PCB, just below the heat sink on the right. I used flash so you can't see it easily but it's just on, not flashing or anything.

I've taken pictures from a better quality camera. I can take pictures of specific if you want.

Thanks again!

[capkid]

Re: Philips 50pfp5532d - no picture but sound

Try isolating your PSU by disconnecting the Z-Sus and Y-Sus to see if your VS voltage returns. Also, check for VA voltage. Steps: Disconnect the Z-Sus, check the voltages, then disconnect the Y-Sus and repeat the voltage check (be sure to unplug AC power before disconnecting boards). Since you're dealing with a "no picture" issue, we want to try to eliminate the sustains as the causes.

[Strike1]

Re: Philips 50pfp5532d - no picture but sound

Okay..done
First I checked Va with everything still connected, it was 0.4V.

Then I disconnected the right board (not sure if it was Z or Y sustain board).
Vg=14.9
Vs= 2.2
Va=0.54

Then I disconnected both boards (left and right)
Vg=14.7
Va=0.3
Vs=0.84

Then had the left board disconnected, right board connected
Vg=14.9
Vs-2.1
Va= 0.43

Then finally tried with everything connected again
Vg=14.9
Vs=2.7
Va=0.43

Not sure it makes a difference, but Vs generally starts off low (around 1.9) and rises slowly to a voltages above. It was changing all the time so the values aren't exact, but at no point was it anywhere near 200V.

[capkid]

Re: Philips 50pfp5532d - no picture but sound

Ok, it appears that we can more definitively say that the power supply is the heart of your issues. Once the power supply is repaired or replaced, the hope is that there is no secondary damage to the sustains.

[Strike1]

Re: Philips 50pfp5532d - no picture but sound

Ok, it appears that we can more definitively say that the power supply is the heart of your issues. Once the power supply is repaired or replaced, the hope is that there is no secondary damage to the sustains.

What does repairing the PSU involve? Where do I begin? Would the kit you linked to on ebay be enough?

[capkid]

Re: Philips 50pfp5532d - no picture but sound

This could take awhile, since that board layout isn't simple (I'm guessing that there are quite a few components on the heat sinks and surface mount components on the back side). The kit to which I linked is for the 42" plasma, and it's a simple cap kit that probably wouldn't correct your issue. I'd still considering replacing the lower voltage caps as preventative maintenance, since those caps tend to fail.

I'd download a copy of the service manual from Tom's site to start. I found this one, but the PSU looks different, so I'm not sure if the manual is applicable to your TV. The chassis ID on the TV's back cover might help identify the correct manual: http://www.toms-service-manuals.com/...&Search=Submit

(1) Check all fuses on the power supply. There may be some smaller fuses that aren't as easily identifiable as the larger, more recognizable standard fuses. They should be labeled with an "F" prefix.
(2) Check output voltages on the board. We already know that VS and VA are incorrect.
(3) If your other voltages are good, I'd focus on the VS and VA tracts.

I haven't had a ton of experience working on Philips plasma TVs, and they can be a bit tricky, so others might have ideas.