Matsushita TM 202g - Flyback is Arcing!

[Kremmit]

My buddy just picked up a "Sky Soldiers" in an old Crystal Castles cab (for $15!!).  The sellers had it running (with a very dim screen) the day he bought it, but it stopped working before he picked it up.  

When I opened it up, I found and replaced a blown fuse on the monitor board (the 1.5 amp one).  There was also a ground somebody had wired (badly) from the monitor chassis to the "F G" terminal on the power supply.  I dunno if this is supposed to be there or not, neither of my other cabinets have this wire.. What's the "F G" terminal for, anyway?  At any rate, I've tried it both with and without this wire connected, with the same results.

With no power to monitor, the board powers up, takes credits, and plays fine.  With power to the monitor, the flyback shoots an arc of blinding death to the nearest metal piece of the chassis.  Is this bad?

Really, I know it's bad.  The question is: why does it do that and how can I stop it?

Thanks!

-Kremmit

[Ken Layton]

With the monitor power disconnected, clean the flyback off real well with some spray cleaner like 409 sprayed onto a rag. Then clean the flyback with a rag moistened with 99% rubbing alcohol. Now look at the flyback very closely with a magnefing glass. You'll probably see a very fine crack or pinhole in the case of the flyback. This can be repaired by a dob of silicone glue and let set overnight before reapplying power.

[Kremmit]

Yup.  

I actually didn't have to do the serious janitorial cleanup & magnifying glass bit.  Once I knocked off the big blob of dust that had gathered over the hole, it was easy to see- it's big enough to push a BB through! (no, I didn't actually put a BB in there  )

I covered it over with some electrical tape just to see if blocking the hole would solve my problem, and bingo! The picture is back & there's no arcing.

Now, I'm just wondering- is the silicone the best way to plug the hole?  And- Is this safe to use as a permanent fix, or should I be replacing the flyback now?  I'm sure hoping the glue is "good enough"- if so, it means I've got a working vertical monitor Jamma cab for $15, plus 1 fuse & some glue- pretty good deal, eh?

Thanks!

[Ken Layton]

You can squirt either clear, white, or black silicone glue into it for a permanent repair. Just remember to clean the area well and let the silicone glue dry overnight before powering up the monitor.

The color of glue to use is dependent on the color of the flyback if you want a pretty repair. If you have a black flyback then get black silicone glue. Me, I just use plain old clear silicone glue.

[Kremmit]

Done- and working fine!

Thanks!

-Kremmit