Monitor neck board arcing; monitor ID help needed

80scoinops

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I have this same monitor discussed in this old thread:

http://forums.arcade-museum.com/showthread.php?t=12641&highlight=510TDB22a&page=5

and the neckboard is intermittently arcing from the wire at GPT to the cap next to it. Was there ever get a solid ID on the chassis in the Frogger thread above? Trying to troubleshoot what could be causing the arc and/or what needs replacing. Monitor is otherwise fine with good picture, no smell of burning. Heard the intermittent snaps during gameplay and found the arcing.
 
Is the ground from the DAG to the board to the actual ground all there? If you're missing any of the links in that ground, you'll get arcing. Most of the time it's from the DAG to the chassis because people remove the ground wire from the neck to the DAG when they cap, and don't seem to replace it... ... no idea why. Could just be a case of a bad joint in the "chassis-DAG-ground" chain?
 
The ground strap looks good, it's grounded at each corner of the chassis, all connections feel solid. Solder points on the GPT and cap on the neckboard look good but that's not always a good indication.

It's never had a cap kit as far as I can tell, but I can't ID the chassis to order a new kit. :) I'll post some pics of it this afternoon.
 
Photos of the chassis boards and neck board with flyback. The arcing is between the ground wire and the squarish blue cap to the left.
 

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The very first thing I'd do is touch up the solder joints on the entire neckboard. It'll take five minutes. Worst case scenario is you're right back where you started.
 
Here's a new one: can't pull the neck board out of there.

Every other monitor, the neck board comes out easily. This one? It looks like it's barely moving about 2 mm, then just stops. There's a piece of dark green plastic that goes through the back of the neck board (in the shape of a V) and looks like it's attached to the ring around the neck (second photo, the dark green ring) where you would expect it to come apart. Anyone know for sure where it should disconnect? I can rock it a little bit, but it feels like it's going to break if I try and force it. Is there some trick (button? release?) to getting this particular one to come apart?
 
mon31.jpg


I would contact Osver and ask him, since he worked on one...
 
Thanks, Mod. It's definitely that Kagi chassis. I see Bob has a cap kit for the 13" version and I'm guessing it works on the 20" monitor also. Osver is gonna double check his when he has a chance, but he said he doesn't recall anything different or difficult about removing the neckboard.

I'll try and work on it some more and see if I can get it out of there. Judging by the image from Bob's site, it looks like I could grab the plastic "V" on the back with some pliers to try and disconnect the neckboard. Hopefully it doesn't come to that, one wrong move and there goes the neck.
 
Finally got the neck board after another 15 minutes of trying to pry it out. No trick to it, it was just iron clad.

Peale - reflowed solder on the joints of the components involved. So far, no more arcing but I'll have to leave it on longer when I have some free time to make sure. The component previously thought to be a cap next to the ground wire looks like a spark gap (?). No burned plastic on that or the ground wire.

Here are a couple of better pics of the neck board.
 

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Glad there seems to be no more arcing. My advice was to resolder the entire neckboard though - not just those parts. It'll take five minutes or less. I guarantee there are more broken joints than just those.
 
Pretty sure it's just dirt, there was no evidence of burning on the pin or the neck. I didn't even notice it on the socket until I took the picture.
 
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