Philips 42FD9954/17s dead

[ryan74]

Re: Philips 42FD9954/17s dead

-Update-

I replaced 10 caps on the board in startup area.
It now powers on ok and stays on but now I have a slight picture issue with input.
The black pics are windows paint
On dark screens i see some white sparkles and up close colors(see pics)
On lighter color screens i notice black dots.
it looks fine without a video input until it powers on.

I have seen posts on sparkles on screen but havent read them before.
I will do some searching here and see what I can find.

The last 2 pics are of paused video. 1 from a distance and 1 upclose.

[ryan74]

Re: Philips 42FD9954/17s dead

http://www.avsforum.com/t/1083055/vi...#post_15046682
Perhaps I'm just seeing dithering from being too close?
I can't seem to capture the few random sparkles or white dots on camera.
I may do more testing but I would like to get into service mode or do a factory reset first if Ican find out how.
I think I may be able to make adjustments to fix it if voltage is off.

[ryan74]

Re: Philips 42FD9954/17s dead

I knew I read this before. I just had to find it. Thanks Tom.
I will go through this soon.

Picture sparklies on some scenes.
If in dark scenes or sometimes even in light scenes a subtle flickering of red, green or blue (or a combination of all three) is visible, then you have the "sparklies" problem. It may look like this, a green mist on the sides of the screen. This affects LG the most, but some Samsung TVs have the problem too. I have never seen a Panasonic with this problem, but I would not rule them out.

Sparklies are the bane of plasma TVs and are caused by numerous problems, including, but not limited to:

Power supply voltages Sustain sub-voltages Timing settings Control board firmware Panel aging

The first three can be fixed in 95% of cases. The fourth is more difficult to fix but can be done by some people with the right equipment (reprogramming the firmware.) The fifth is not possible to fix, without replacing the panel, which is too expensive to justify replacement in most cases. Luckily, the fifth is usually correctable and is a result of the first three not being in specification.

Power supply voltages The power supply voltages are different and unique to each panel, due to manufacturing variations and model specific parameters. They are always indicated on the panel with a sticker like this.

You will need to get out your DMM.

If you have a manual ranging multimeter (with, for example, 200m, 2000m, 20V, 200V, 100V for the DC range) set it to the 1000V DC range (or closest range above 200V, e.g. 500V or 600V.) Some Vs voltages can exceed 200V on some TVs.

If you have an auto-ranging multimeter, set it to DC volts.

Then find the test points on the power supply. In my limited experience the best place to test these voltages is on the output connectors of the power supply, which are usually labelled, with the positive stuck next to one of the pins (jammed in there) and the negative in a spare screw hole in the frame. Here I am probing the Vs voltage on this TV. As can be seen in the image, the voltage measures 187.9V. It should measure 186V. This 1.9V difference can make a substantial difference to the performance of the PDP.

Even if the voltage is less than 1V out, adjust it down to meet the sticker rating as close as you can. (I adjust to within 0.2V.)

The adjustment is usually near the output connectors and is labelled. SLOWLY turn it one way or the other to meet the required output voltage.

Also check Va, which is around 60V. Adjust it in the same way.

Now the voltages are in spec, check the picture. Has it improved? Don't be afraid to say it hasn't - this doesn't fix all sparklies. Sometimes it can improve them slightly, but not completely. If so, on to sustain voltage adjustments.

Sustain sub-voltages On the Y-sustain, there are sometimes additional voltages. These are generated from the main Vs and Va voltages by one or more voltage converters. They look a bit like these. Samsung PDPs tend to put the converters on the board itself and not on little daughter-boards.

Sometimes there are also converters on the Z-sustain for the Zbias voltage.

You are looking for the potentiometers (indicated by the red arrows) to adjust the voltage settings. You are also looking for the test point for each voltage. You may need to refer to the service manual to find the test points - as they are often in obscure places. The sticker indicates the correct voltages; sometimes they are written in a strange order so you may need to refer to the manual for what each number indicates.

The method of adjustment is the same as for the Vs and Va.

Still not looking great? Sometimes this is caused by timing settings... I will discuss that in another post in this thread shortly.

Va/Vda/Vdata = Horizontal Data Voltage. This is used to "write" to the pixels on the display and store the image during the addressing phase. Failure is very rare, but can happen. If it did fail, the panel would likely still glow, but you'd have no picture. Most likely the failure is due to shorted COF chips, on the panel, which writes off the TV.

Vs/Vsus = Sustain Voltage. Main power bus in the TV. Used to make the written pixels glow due to electron excitement, which causes UV emission, which is then converted into visible light using the phosphors. Failure causes no picture. Low voltage causes maldischarge (purplish look, uneven brightness, flickering pixels, etc.)

[ryan74]

Re: Philips 42FD9954/17s dead

panel-fpf42c128128ub-72
Fujitsu

Rating:
+3.3/+5/+75-90/+50-70V.

0323 connection
1)va=62.7v.
2)nc=7.2mv.
3)vcc=5.14v.
4)g
5)g
6)g
7)nc=7.2mv
8)vs=79.6v
9)vs=79.6v
10)vs=79.6v

0333 connection
1)vcc=5.14v
2)g
3)g
4)g
5)g
6)nc
7)vs=79.6v
8)vs=79.6v.
9)vs=79.6

I'm not sure these readings are good. Can someone confirm.

[tom66]

Re: Philips 42FD9954/17s dead

This is also visible on the 37" Philips that I am in the process of fixing.

The only adjustment on these panels is "Isk" on both sustains. Try tweaking that. There is no ramp-up/ramp-down control like on LG or Samsung and the -Vy/Vsc are fixed.

The Vs/Va are not adjustable because Philips didn't include potentiometers.

The exact required panel voltages are printed on a separate sticker. e.g. Vs=86.9V, Va=60.2V. It varies from panel to panel. I think Philips just stuck with a fixed voltage and hoped it would work. This may be the problem.

[ryan74]

Re: Philips 42FD9954/17s dead

I figure this is where you said to adjust in pics.
I dont have a stand so it is face down on a table. Im going to have to figure out how to keep it upright while adjusting.

-Edit- I cant see any other voltage ratings for panel unless it is under the boards.

[tom66]

Re: Philips 42FD9954/17s dead

Looks like them. Be very careful and adjust it slowly. If you can get a friend, then that works too .

You need to take off the plastic frame, so that you can see the rest of the panel stickers.

[ryan74]

Re: Philips 42FD9954/17s dead

Im going to try adjusting today. First time I have done this on a board so I want to make sure I don't mess up.
I think I should be safe if I use small adjustments like numbers on a clock right?
make an adjustment turning right from 12 to 1, if picture is worse, turn it left to 11?
Do I need to wait long between adjustments?

I assume 1/4(0.25) turns are too much

[tom66]

Re: Philips 42FD9954/17s dead

Well, if it is anything like LG or Samsung plasmas, then adjusting it too far simply causes poor picture -- i.e. overdischarge or underdischarge.

Adjusting it very slowly is a good idea; just turn one. If picture gets worse, turn it the other way. Getting it right will require careful tweaking of both.

[ryan74]

Re: Philips 42FD9954/17s dead

The ISK didnt seem to do anything so I started messing with the adjustment on power board.
Sparkles went awawy 99% after slight adjustment at loc 3026.

[ryan74]

Re: Philips 42FD9954/17s dead

White sparkles are gone and from a distance everything looks good but up close i see color.
Im not sure if this is normal.

[ryan74]

Re: Philips 42FD9954/17s dead

Some sparkles came back as monitor warmed up and colors got a little worse. Adjustment on power board is maxed. Still can't find voltage sticker on panel. I may try replacing more caps and see what happens.

[FALC0NDRIVER]

Re: Philips 42FD9954/17s dead

-Update-

I replaced 10 caps on the board in startup area.
It now powers on ok and stays on....

Resurrecting this thread since I have the same problem on the same tv. Ryan74, which 10 caps did you replace in the startup area?

[ryan74]

Re: Philips 42FD9954/17s dead

Resurrecting this thread since I have the same problem on the same tv. Ryan74, which 10 caps did you replace in the startup area?

check post 40. I think most of those caps I replaced I marked location on pic below. If I remember correct the startup is 10v so its probly the 16v caps.

I still have the tv but it still has sparkle issues so im going to part it out some day.

[tom66]

Re: Philips 42FD9954/17s dead

The sparkles issue you refer to is absolutely normal for a plasma. It's called dithering. Sparklies are only a problem if they are visible from approx 10 foot. A plasma panel only has single bit depth... pixels are on or off. So it dithers them to get full 10 bit colour, which works well when viewing the TV from approximately 10 foot. You will notice this on Panasonic, LG and Samsung plasmas.

[ryan74]

Re: Philips 42FD9954/17s dead

Sparkles get worse over time. when it is first turned on it is probly ok from 10ft. but after 20-30min. it is very noticable on dark and light images.

[tom66]

Re: Philips 42FD9954/17s dead

You need to find what's drifting.... take a hot air gun or hairdryer to parts and see if you can make it occur quicker when bits are heated.

[FALC0NDRIVER]

Re: Philips 42FD9954/17s dead

Thanks Ryan. I'm on it

Appreciate The Help

[postrich]

Re: Philips 42FD9954/17s dead

Help ! What happened with this thread ? I have exactly the same TV with exactly the same readings. What piece or part should I test next or replace... (newbie).

[postrich]

Re: Philips 42FD9954/17s dead

Eek. While testing, I shorted pins 5 & 6 (top right from how I'm looking at it) on the TNY256 (loc7500). Pin 5 read approx 156vdc and still reads that. The TV now does the same standby light, then clicks and gives the green, but then clicks off and blinks red. Any ideas on what I broke ? All the readings still look pretty much the same as the tests from RYAN74 in this thread.

I have read this thread probably 25 times now and I learn something more each time. Thank you all for your efforts and knowledge sharing. I would love to fix my first TV and reap the rewards of this heavy beast, so any help would be super appreciated.