PIONEER PDP505PE Green Dots in the Centre of the Screen

[sarnade999]

Hi, The Pioneer TV is approx. 9 Years old. For the last 6 Months I have been experiencing a cluster of Green Dots generally in the Centre of the Screen. These Dots are more intense on Red backgrounds and are visible on Skin Colour as well. You can barely notice them on other background colours. I have tried different sources of input and all have the same symptoms. I have replaced the Y Drive Assembly Board ( This was a second hand one ), but the symptom was still present. I have since put back the original Board.
Any Advice would be most appreciated.

[sarnade999]

Re: PIONEER PDP505PE Green Dots in the Centre of the Screen

Please Find attached an Image of the Symptoms I am getting....Thank you

[martino]

Re: PIONEER PDP505PE Green Dots in the Centre of the Screen

That's a plasma? Might be as simple as re adjusting voltages.Did you open the back?

[sarnade999]

Re: PIONEER PDP505PE Green Dots in the Centre of the Screen

All the Voltages that I could check with a DVM checked out okay. Someone did suggest I turn off the V-Scan (Rotate the potentiometer fully anti-clockwise).
Not Sure about this, and anyhow I cannot find the V-Scan adjustment. Its suppose to be located on the Y-Sus (Called "Y Drive" for Pioneer) PCB. So I'm stuck at the moment.

[Alastair E]

Re: PIONEER PDP505PE Green Dots in the Centre of the Screen

Hmm--Tis an odd fault....

So--In Real life,(difficult to tell in pics)--NO other part of the picture is affected....?

How many hours on the set?

With all voltages correct, and only a small vaguely shaped blob thats bad, I'm thinking the panel itself....

[tom66]

Re: PIONEER PDP505PE Green Dots in the Centre of the Screen

Looks like 1SF maldischarge (maldischarge in 1st subfield, for lowest video intensity, LSB of video data.)
I'd focus on the VSET voltage on Y-drive - try increasing it.
As the panel ages, some voltages may need to be adjusted.

[sarnade999]

Re: PIONEER PDP505PE Green Dots in the Centre of the Screen

Thanks again for all your advice.
However, I cannot locate VSET on the Y-Drive pcb. I have gone through the PCB with a magnifier glass and have listed below the Presets and Various Test Points.

TEST POINTS:
YSUS-MSK, YSUS-B, YSUS-D1, YSUS-D2, YSUS-G, YSUS-U2, YSUS-PD
VH-UV-PD, YPR-U, SI, OC1, OC2, CLR, CLK2, LE, SUSOUT, YRSV-2
YDD-PD, Y DRIVE-PD, YDD-PD, PN-MUTE, DRIVE-PD,
-VOFS, VOFS-ADJ,

PRESETS:
VR2201, VR2202, VR2203, VR2204, VR2402
VR2401 Labelled "VH-CONT" ( The only one with a Label)

Because of only having 6 Presets, most of the Test Points cannot be adjusted from the Y-Drive PCB. And not having Labels for the Presets, making it impossible to know what you are adjusting unless you have a schematic, which I do not have.

Pioneer are not making it easy !!.

Thanks again

[R_J]

Re: PIONEER PDP505PE Green Dots in the Centre of the Screen

Download the service manual. Mark the controls original position with a felt pen (or something like that) observe the area with the problem and make a slight adjustment one way then the other and see if it makes the problem better or worse. To adjust it correctly you need a scope.

[sarnade999]

Re: PIONEER PDP505PE Green Dots in the Centre of the Screen

Thanks R_J.
The Service Manual doesn't help in this situation.
Unfortunately I do not have an oscilloscope, I assume you are referring to adjusting the "VH-CONT".

Thanks again

[Wtduck]

Re: PIONEER PDP505PE Green Dots in the Centre of the Screen

Hi guys, I have a similar problem with my pioneer 50" plasma model PDP505HD. It started with dark pixels (purple/green color) on the screen and now it starts up with a full black screen and takes about 5 minutes until the picture comes up. It still has the dark patch as per the picture that sarnade999 posted.

[freakaftr8]

Re: PIONEER PDP505PE Green Dots in the Centre of the Screen

Hi guys, I have a similar problem with my pioneer 50" plasma model PDP505HD. It started with dark pixels (purple/green color) on the screen and now it starts up with a full black screen and takes about 5 minutes until the picture comes up. It still has the dark patch as per the picture that sarnade999 posted.

I've had this symptom before. What's going on is it this is a TV in the panel has aged significantly over a lot of use the vsus drive needs to be raised until the black patch disappears and the sparkles clear don't raise it too much but put a meter on it and monitor the voltage. Or you could have low voltage on the vsus drive which could also cause the black spot in the middle of the screen as The Guess cannot charge properly if the voltage is dropped too low on the vs output of the power supply.

before you do this your first step is to measure all output voltages of the power supply and confirm them with the label on the panel if your VSUS drive voltage is too low don't cause this issue

[freakaftr8]

Re: PIONEER PDP505PE Green Dots in the Centre of the Screen

for all other pioneers exibiting the green sparkles are they near the center top of the screen? I had a few pioneer plasmas do this and what it turned out to be was excessive buildup of heat from the power supply causing that area of the screen to get excessively hot I have tried adjusting voltages I've tried scoping waveforms and nothing seemed to help until I put a fan in the center of the TV blowing out pulling the heat from the power supply away. If you noticed pioneers have 2 or 3 fans on the top some don't have any I used a computer PC fan power supply fan and wired it in series with the other fans. you could try this. Next time you get the screen sparkles take a fan and blow inside the TV or the top vent holes are see if the green sparkles disappear. This will tell you if heat related

[caspe15]

Re: PIONEER PDP505PE Green Dots in the Centre of the Screen

I hate to raise this dead thread, but I have the same issue (green spots in center) on my Pioneer Plasma Pro-1110 panel. I've had no luck finding a service manual or even parts. I'm sure being so old, getting parts won't be easy. Anyone know where to find a service manual? How about a known fix? It seems like most of the posting here and other places are just guesses. I heard voltage adjustments, cooling, etc, but nothing too specific. Regarding adjusting any voltages, I haven't opened the case yet, but it sure seems unlikely that there will be anything that is adjustable. Given how heavy this thing is and the fact that mine is hanging on the wall, I don't want to spend time taking it down until I have a good plan.