PVM 2044QM Troubleshooting Update: Screen Wobble

[Skykid]

UPDATE 10/11/13

After doing some adjustment to the display (it was seriously underscanned) and the vertical linearity to reduce a lower screen warping, pretty much everything is ok except an unusual oddity I can't quite figure out.

Here's a short video:

http://www.youtube.com/watch?v=73dbp5Xp ... e=youtu.be

The upper portion of the screen has this wobble only when there's a predominantly black background. In-game is usually fine, unless there's a point when the display is particularly dark.

The strange thing is, if I use the horizontal centering and shift the screen to the right, it completely solves the problem: but I'm losing around a CM of screen!
Shifting the image to the left exacerbates the problem to the point that the entire screen rolls.

Anyone have any idea what may be causing this? It's not something that's prevalent during games, because the conditions required are normally on title screens, or like the video on Contra's continue screen - but occasionally it crops up when images fade in and out.

At the moment it's a toss up between overscanning the screen to almost a CM loss on the right side or accepting this irritating wobble cropping up now and then, but I'd like to pin down a way of solving it if possible.

Thanks for the help!






Original Post:

Grabbed a PVM from a really nice guy on ebay who was moving house and let me have it for the grand sum of £5. Back breaking work to get it across London, but did the job with a little help from my friends.

Now I'm trying to figure out how to set it up, and failing.

Using a BNC -> Scart adaptor wired for Euro. There are a load of inputs in the back and it's unclear what goes where precisely. Every time we put the green in, it turns the picture off - but then I don't know where it's meant to be. Any picture I've managed to get is missing a colour, so either looks greeny yellow or red.

There is a switch on the back between component and RGB, with RGB seeming to get to the closest correct image. There are four buttons on the front with component and VTR buttons bringing up the pictures depending on what leads go where.

With the yellow on its own plugged into 'Video' I get what looks like a composite image, and I can channel the audio from the TV speakers, but again the colours aren't correct.

Anyway, component is obviously what the PVM is all about. System is 60hz SNES. If someone can help (Ian, I know you have one) that would be great. Here are some pics of the set and inputs:

[Skykid]

Here's a pic of Turbo.



Ken is meant to be red, but the whole thing is missing a channel and is tinted green. I have no idea why the green wire turns the picture off. This capture was done with R, B and Y plugged in, and switch on RGB.

[ZellSF]

The inputs seems obvious to me:

R/R-Y: Either RED signal of RGB or Red/Luma signal of Component (red component cable)
G/Y: Either GREEN signal of RGB or Sync signal of component (green component cable)
B/B-Y: Either BLUE signal of RGB or Blue/Luma signal of component (blue component cable)

The switch determines if you're using the first set (RGB) or second set (R-Y/Y/B-Y) of inputs. What exact cable you're using to connect the SNES to the PVM might be useful to know.

[Skykid]

With this setup:



I get no picture. If I replace the green with yellow I get a black and white image, but the green instantly kills it again. Switch is on component.

I'm using a euro scart with the snes.

Thanks for the help.

[ZellSF]

Disclaimer: I'm not knowledgeable about PWMs I just thought those inputs seemed obvious.

Try moving all those three cables to IN ports not OUT ports (move all connectors one step left), use the yellow composite cable (I think you said you had one) for SYNC IN. Set the switch to RGB.

Assuming you're trying to get RGB working and not component. I don't think the SNES directly supports component unless modded.

[22point8]

Service Manual: http://sdrv.ms/18NlFfL

[cools]

What he said. As long as sync is connected on an IN, any combination of 1-3 colours will get you an image, though red should be into the R in etc if you want the picture to be displayed correctly.

Switch to RGB

[Skykid]

https://lh3.googleusercontent.com/-KAf7 ... 192822.jpg

^ This exact setup on mine renders no image at all, screen is dead as a doornail, and it's switched to RGB.

EDIT:

Got it, what a facepalm!

There's a button on the front panel noted EXT which is off by default. Switching it on obviously pipes the sync lead to the TV and wallah, I got a picture. And it's beautiful. ^_^

Thanks for the help chaps, now I need to open the monster and do some overscan settings etc.

Can anyone tell me about recording settings on one of these? It's got a 'memory' button that I assume keeps the settings, but not for multiple setups?

[22point8]

https://lh3.googleusercontent.com/-KAf7 ... 192822.jpg

^ This exact setup on mine renders no image at all, screen is dead as a doornail, and it's switched to RGB.

EDIT:

Got it, what a facepalm!

There's a button on the front panel noted EXT which is off by default. Switching it on obviously pipes the sync lead to the TV and wallah, I got a picture. And it's beautiful. ^_^

Thanks for the help chaps, now I need to open the monster and do some overscan settings etc.

Can anyone tell me about recording settings on one of these? It's got a 'memory' button that I assume keeps the settings, but not for multiple setups?

Also, glad to see it isn't just mine that look that bad on composite.

[fagin]

Considering you'd only paid a fiver, I was going to suggest you can find out your ****ing self!

Glad you got it sorted.

[Skykid]

Considering you'd only paid a fiver, I was going to suggest you can find out your ****ing self!

Glad you got it sorted.

Ha ha, good price for sure!

Thanks for the memory save tip. Shame I'm limited to one setup save but whatever.

This model has no on screen geometry options etc, so I need to open it up for a little tweaking. I'll try to be less of a pussy than Ian and jump right in without killing myself outright, but at the moment my only issue is with a slight oversaturation of colour (if it is that.)

It seems it could be sharper and there might be something that can be adjusted to make the pixels a little crisper. I don't know if anyone knows what does what internally that I could try going for?

[22point8]

Focus, on the flyback. But experiment with lowering the contrast too, and don't mess with gains/drives and bias, or screen volts. The screen volts seem to majorly affect green bias.

Only adjust geometry and focus.

[Skykid]

Focus, on the flyback. But experiment with lowering the contrast too, and don't mess with gains/drives and bias, or screen volts. The screen volts seem to majorly affect green bias.

Only adjust geometry and focus.

Cool thanks for the heads up. Will get on it tomorrow. I did adjust the pots for rgb gain in the front of the tv (see pic) but it only has a small tint effect, and in the end I just reduced the three to zero (off). I'm assuming you're talking about a central gain pot inside the chassis?

[22point8]

On mine the green gain on the front panel doesn't do anything. The front panel ones are general, the ones inside are red and blue bias and drive for 6500, red and blue bias and drive 9300 and red (R) and blue (B) bias (next to sub-brightness) for RGB mode. The service manual isn't actually clear on that it just says 'adjust rv1709' or something but inside its too difficult to actually see what numbered thing you are adjusting, and it doesn't help that these pots are right next to the big power supply board! Only mess with these if you have a colorimeter or spectrophotometer. Outside of the geometry settings you need an oscilloscope or multimeter, I don't have those and have no reason to adjust those things anyway.

[Skykid]

THIS THING IS PORN

[ninn]

MOIRE PORN

[matrigs]

THIS THING IS PORN

there is no hope for humanity

[speedlolita]

THIS THING IS PORN

Welcome, to the master race.

[Skykid]

Updated the OP:

UPDATE 10/11/13

After doing some adjustment to the display (it was seriously underscanned) and the vertical linearity to reduce a lower screen warping, pretty much everything is ok except an unusual oddity I can't quite figure out.

Here's a video I took:

http://www.youtube.com/watch?v=73dbp5Xp ... e=youtu.be

The upper portion of the screen has this wobble only when there's a predominantly black background. In-game is usually fine, unless there's a point when the display is particularly dark.

The strange thing is, if I use the horizontal centering and shift the screen to the right, it completely solves the problem: but I'm losing around a CM of screen!
Shifting the image to the left exacerbates the problem to the point that the entire screen rolls.

Anyone have any idea what may be causing this? It's not something that's prevalent during games, because the conditions required are normally on title screens, or like the video on Contra's continue screen - but occasionally it crops up when images fade in and out.

At the moment it's a toss up between overscanning the screen to almost a CM loss on the right side or accepting this irritating wobble cropping up now and then, but I'd like to pin down a way of solving it if possible.

Thanks for the help!

[Skykid]

Anyone?

[Skykid]

These are the pots I can play with:





One of you tech maniacs must have an idea of why this might occur.