Panasonic VT60/VT65 Plasma Cyan & Pink Blobs

[Eiji]

I am currently having an issue with my Panasonic TX-P55VT65B Plasma TV.

It currently has 250 hours clocked on it. I have been checking the uniformity of the panel ever since I got this TV and it was fine up until about the 220 hour mark. Using white and grey image slides or even the TVs built in EPG shows the left side of the screen has a cyan tint and the right side has a magenta/pink tint.

I tried to take a picture of this with my mobile phone camera but the camera on the phone is rubbish and cannot take an accurate image of the problem so I have attached an image of a TV that has the same problem that I found on Google image search but the problem isn't as bad as the image yet.

Could changing VSUS in the service menu from LOW to HIGH cause green and pink blobs to appear? I'm thinking maybe the blobs on my set may have been caused by VSUS set to HIGH in service menu, panel luminance HIGH and running the built-in white scrolling bar overnight as I needed to get rid of some very stubborn image retention which did disappear but at the cost of the tints appearing

Is there any way to resolve this without opening the TV up and bumping up the VSUS via the pots? Could it be that a charge has been built up in the phosphors causing the tints?

What would the solution be? Thanks!

[tw2005]

Re: Panasonic VT60/VT65 Plasma Cyan & Pink Blobs

Under warranty? What do the test patterns look like in srv tool, aging?

[tom66]

Re: Panasonic VT60/VT65 Plasma Cyan & Pink Blobs

There is no point claiming warranty on this, as Panasonic will in the best case fob him off to a replacement LED TV which wouldn't even come close to this panel. They don't have any parts left for these.

This is a common issue and appears to be caused by an incorrect factory VSUS setting or failure to compensate for panel aging. You should try the LOW/HIGH setting. However it is important to note that in most cases a better result is achieved by removing the case of the TV and verifying instead that the LEFT VSUS and RIGHT VSUS are set to the same voltage - these power the SC & SS and are independent from one another.

[Eiji]

Re: Panasonic VT60/VT65 Plasma Cyan & Pink Blobs

Ok, I just tried alternating between the LOW and HIGH VSUS setting in the service menu and it appears to make no difference to the tints. In the service manual it states the reference voltages for low and high setting is 210V / 215V. What is the highest safe voltage I can go on this set?

TV is under warranty and I can't see the tints with the scrolling bar or srv tool and ageing in the service menu but I can see them in the EPG and other solid colour images that I have.

[Eiji]

Re: Panasonic VT60/VT65 Plasma Cyan & Pink Blobs

Also, which pots need to be adjusted and where are the test points to connect the multimeter?

I have added an image which isn't of my TV but the same model. It would be great if you could point out where on the image the pots and test points are so that I can be 100% sure.

Thanks.

[tom66]

Re: Panasonic VT60/VT65 Plasma Cyan & Pink Blobs

The pots are on the power supply. I believe they are marked VSUS_L and VSUS_R. Looking at your PSU though I am not sure if your set has two VSUS supplies. Therefore the issue might be different.

[Eiji]

Re: Panasonic VT60/VT65 Plasma Cyan & Pink Blobs

I have found a clearer picture of the power supply board. It says VSUS_R for one of the orange pots. Would that mean there is a VSUS_L somewhere else? The other orange pot seems to say VDA.

Would the issue still be fixable with these pots?

Thanks.

[aaronwt6]

Re: Panasonic VT60/VT65 Plasma Cyan & Pink Blobs

V_Sus L is in the bottom right of the picture. Mostly hidden in the picture by the heat sink.

[Eiji]

Re: Panasonic VT60/VT65 Plasma Cyan & Pink Blobs

V_Sus L is in the bottom right of the picture. Mostly hidden in the picture by the heat sink.

Yes, you're right, I can see it now! Thanks for pointing it out.

Now, where would I connect my multimeter to test the voltage for each VSUS pot? I suppose I can use the metal chassis as ground?

[tom66]

Re: Panasonic VT60/VT65 Plasma Cyan & Pink Blobs

VSUS_L can be tested across the brown/white connector going to the left hand green board (SC board.) VSUS_R can be tested on the right hand board.

You will need to set your multimeter to a range higher than 200V (for example 500V, 600V, 1000V.) If it's autoranging DC volts should be fine. A digital meter is necessary. Make sure the red probe is in VOLT/OHM jack and black is in COM. (Whatever you do, do not put it in the A jack!) Measure across the brown and white connector - caution, high voltage! Careful not to slip. Both boards should be around 200~220V and matching. Test on variable picture content - from a black screen to normal TV.

Caution! Do not touch any exposed metal except for the back metal chassis of the TV.

[Eiji]

Re: Panasonic VT60/VT65 Plasma Cyan & Pink Blobs

Thanks for the info tom66.

BTW this is strange to me but I've been running the scrolling bar with the VSUS set to the default of LOW and contrast at 90 for about 5 hours while I was out. I just checked and the pink tint has disappeared and the cyan tint is barely visible.

Any idea as to what is going on? Not sure what to expect in the morning but I will switch the set off for now.