PVM 2950 QM

[the-force]

Does anyone have an idea what causes such OSD distortions (green trailing) on a PVM 2950 QM? The image over RGB looks flawlessly.

[buttersoft]

Looking at the service manual, that set has a slightly odd but perfectly functional way of running the OSD. The R,G,B out of the micom (with no blanking) feeds the jungle inputs R, G+B, and blanking, respectively. Assuming this is correct, you would presume the OSD lines themselves are fine. If blue was bleeding as well, you would have a faulty micom. There's no components in the way to interfere.

You show a picture of the white text of the OSD with green bleeding to the right. Does other white text bleed, with the OSD off? How about bright white objects? And bright green objects? The longer the horizontal line, the longer the bleed? Does the problem reduce as you turn down the brightness? Is there an overall cast to the screen and what colour is it? If so, I reckon you have a problem on the neckboard.

Remember to be safe if you're going to open the set, of course!

[the-force]

The bleeding only seems to affect the OSD.

[mikejmoffitt]

From these pictures your image looks extremely blown out, with the upper range of colors completely clipped. Are you sure your RGB cable is built correctly for your SNES? Also, is termination enabled for the RGB inputs (if it is controllable)?

That kind of bleeding is typical of a tube with poor emissions, so if it's had a lot of use, there may not be a lot you can do about it besides trying a "restoration" process using a tube tester / rejuvinator.

[the-force]

Sorry, I took the pics with the camera of my phone. The colors look okay in reality. Maybe I can upload better pics.

When it is the age of the tube, why is the bleeding then only visible in the OSD?

[mikejmoffitt]

The OSD may simply be a higher intensity than the incoming signal. It is possible that there is an electrical issue before the tube, but I highly doubt it.

[buttersoft]

The OSD may simply be a higher intensity than the incoming signal.

Now that's something i didn't think of.

the-force, are the whites in a signal you input through your SNES, using 240p test suite or whatever, as bright as the whites in the OSD? Do they show up over the 100IRE test? That might a good image to put up and turn the OSd on and off, to see what happens. Does the bleed start going away at all as you lower the brightness or contrast using the controls on the front, or get worse as you raise them?

[the-force]

Hi buttersoft,

thanks for your reply. Here are the images from the 240p test suite.

Minimum Brightness:


Standard Brightness:


Unfortunately it seems that the OSD indeed has a higher intensity. When I lower the brightness, the bleeding almost vanishes.

Best regards

[buttersoft]

Alright, this is the point where I admit I’m not sure if the OSD is meant to be higher intensity. It’s going to help it show up over a bright screen, so maybe. Perhaps someone else with a 2950 could confirm.

If the monitor is bright enough for you when gaming, i wouldn’t sweat anything. I’m going to go against what Mike said as the high-end tubes Sony made tend not to cause this kind bleed - it's far from impossible, i just don't think it's likely. If I had to guess I’d go with one of the solid-carbon resistors on the neckboard drifting out of spec, in the voltage divider for the screen grid - I’ve seen an almost identical problem on five or six PVM-2730’s, and these look to have a similar neckboard. Or it might even be one of the electrolytics on the neckboard. And there would be a few other potential causes as well - that's the problem with remote diagnosis. But again, if the set is fine to game on, and otherwise nice and bright and colourful, I wouldn’t say there was a problem in this case.

[the-force]

I examined the whole thing a little further. Although I have set the color temperature to 9300 K, the picture looks a little reddish when the brightness is set above the standard value.

You hardly notice it while playing.



When there is no signal, the picture looks like this (close-up view).



I ordered a RM-Y137A remote control from Sony which should be compatible with this PVM. Maybe the color can be corrected in the service menu (?).

[mikejmoffitt]

So... monitors have historically given bad names to these options, but generally you should not be adjusting "brightness" other than to get the black level correct once during setup. To adjust total intensity in proportion, you want to change "Contrast".

However the truth remains that your OSD is much brighter, and now also that your red bias is a bit high. The color should be correctable in the service menu as you've noted.