Nanao MS8-25 display/signal interference issue

For monitor related issues
Post Reply
User avatar
Posts: 415
Joined: November 3rd, 2008, 7:18 am
Location: Phuket

Nanao MS8-25 display/signal interference issue

Post by kazuo »

Hey everyone,

Been noticing this issue pop up off and on for me over the last year or so. Not really sure what the deal is, but it's become more persistent in the last couple of weeks and I'm no longer able to look the other way. This is on a MS8-25 with a Mean Well power supply (QP-150-3A) installed in the cabinet. The problem manifests itself as faint, white crackly lines appearing on the picture, usually in a diagonal orientation. The intensity and frequency seems to change depending on how bright or dark the on-screen color palette is, as they seem to disappear entirely on dark screens and reappear as the screen brightens up. The screen otherwise looks great, performs well, and doesn't exhibit other abnormal behaviors. I don't hear any weird arcing or see any physical damage to suggest that the tube/yoke might be damaged.

Initially, I noticed this more when using the MiSTercade or the JAMMA Expander (also a MiSTer interface for JAMMA), and occasionally with my CPS2 multi, but now I am seeing it on basically everything I own. Amusingly, this doesn't seem to be a problem with a PGM and Espgaluda. I searched around and found some discussion around switching power supplies being an issue, and tying earth + DC ground together as a fix, but I don't want to start doing anything without some input from more knowledgeable people. Some pics below, sorry for the bad photos, I am neither a professional nor the owner of a good smartphone.

Thanks for any help!

Post Reply