PVM 20M4U

The place for all discussion on gaming hardware
Post Reply
Ultrax
Posts: 3
Joined: Sun Sep 27, 2015 11:14 pm

PVM 20M4U

Post by Ultrax »

I recently purchased a PVM 20M4U, as seen in the picture it has 3 horizontal lines across the top of the screen. What could be wrong and how would I go about fixing this? Image
User avatar
BazookaBen
Posts: 2078
Joined: Thu Apr 17, 2008 8:09 pm
Location: North Carolina

Re: PVM 20M4U

Post by BazookaBen »

Have you messed with the underscan and overscan buttons? I normally only see those lines when I use underscan mode.
User avatar
Gered
Posts: 61
Joined: Thu Mar 26, 2015 1:24 pm
Location: Toronto, Canada

Re: PVM 20M4U

Post by Gered »

I have not had this issue, but I recall reading posts from other people who have run into it and being told to go into the service menu and adjust the V BLANKING setting.
User avatar
donluca
Posts: 852
Joined: Sat Feb 28, 2015 8:51 pm
Location: Italy
Contact:

Re: PVM 20M4U

Post by donluca »

I have this as well on my BVM 14M4DE.

It is caused by a bad capacitor Sony put in. It's documented and they used a wrong value cap. Search a bit on Google and you'll find the Sony sheet reporting this issue and how to correct it.

If you don't want to open your monitor and replace the cap, you can play with the V Blanking setting to send the lines out of the screen.
Mind you, this is not a definitive solution and you may find yourself with the upper part of the image cut out.
User avatar
BazookaBen
Posts: 2078
Joined: Thu Apr 17, 2008 8:09 pm
Location: North Carolina

Re: PVM 20M4U

Post by BazookaBen »

donluca wrote:I have this as well on my BVM 14M4DE.

It is caused by a bad capacitor Sony put in. It's documented and they used a wrong value cap. Search a bit on Google and you'll find the Sony sheet reporting this issue and how to correct it.

If you don't want to open your monitor and replace the cap, you can play with the V Blanking setting to send the lines out of the screen.
Mind you, this is not a definitive solution and you may find yourself with the upper part of the image cut out.
Interesting. Does this happen in the M2 series as well?
User avatar
Xan
Posts: 760
Joined: Mon Sep 23, 2013 12:04 pm

Re: PVM 20M4U

Post by Xan »

To fix horizontal red, green and blue lines creeping into the top of the
> NTSC monitors:
>
> 1. Press the 'Menu' button
>
> 2. After the menu appears, press 'Enter' and 'Degauss' at the same time. If
> the screen is then degaussed, that means that you didn't hit them at the
> same time so try again.
>
> A. Hopefully you just entered 'Service mode'. You should see a display
> resembling this:
>
> OTHER >163 91
> V. BLANKING <60>
>
> B. The number 91 is the feature we are adjusting (in this case, vertical
> blanking).
>
> C. The number 163 is the value that vertical blanking is currently set to.
>
> 3. Use the 'Menu' and 'Enter' buttons to scroll to #91 if you're not already
> there.
>
> 4. Use the + and - buttons to adjust the vertical blanking. As you move up
> or down, you should
> notice the problematic lines going away.
>
> 5. When you find the right setting, press 'Degauss' and the word 'Write'
> will appear on the screen.
>
> 6. Immediately press 'Degauss' again to save.
>
> 7. Turn the monitor off and then on again and you're ready to roll.

http://archives.bengrosser.com/avid/200 ... g02329.htm
This guide isn't on the net anymore, but it said to replace C584 (2.2µF) with a high ripple 1µF cap for this issue. An ESR meter could help a lot in verifying the issue too.
User avatar
donluca
Posts: 852
Joined: Sat Feb 28, 2015 8:51 pm
Location: Italy
Contact:

Re: PVM 20M4U

Post by donluca »

BazookaBen wrote:Interesting. Does this happen in the M2 series as well?
The entire M series is affected AFAIK.

@Xan: that was the cap to replace IIRC, should check my history but I'm lazy today :P
User avatar
Xan
Posts: 760
Joined: Mon Sep 23, 2013 12:04 pm

Re: PVM 20M4U

Post by Xan »

50-series can be affected as well, according to this thread.
Post Reply