Arcing/buzzing wire and vertical rollover.

Hey guys,
I have two issues which are unrelated.

First and most concerning to me, there is some purple arcing and buzzing going on from a wire which looks like it has braided shielding(?).
Can I just put some heat shrink over that?

And second, I have some vertical fold-over/roll-over on the top of the screen.
Before someone asks, I have tried adjusting the pots to no avail.
I suspect it might be a cap issue, but I honestly am a bit afraid to recap it myself. So, I'm hoping someone might be able to give me some suggestions before I have to resort to that.

I'll see if I can get some pics and maybe a video of the arcing tonight.

What type of board is it ?

Also I would not recommend just "heat shrink" over the wire. If it is arcing and buzzing that could be a shorted connection and can ultimately get worse, possibly damaging your system permanently. If it is a braided wire sheath, there may be a separate inner conductor under the braid and they could be shorting out. Don't think I have ever seen a braided wire on an MVS board. Post pics if you can.

If your talking about Capacitors on the Neo Geo mother board, they are normally there for the sound portion of the board. The other caps are generally used a DC (power) filters, on the MVS. There are some other folks on the forums who are very knowledgeable in this area, but I don't think the Capacitors on the MVS board would be the issue your having with the video.

I didn't say either of those were on the board.
The caps I am referring to would be for the monitor.
The braided wire might be some sort of ground?
I'll get pics in a few minutes.

http://little-legion.com/screen/folding.jpg
http://little-legion.com/screen/folding2.jpg

MoriyaMinakata said:

http://little-legion.com/screen/folding.jpg
http://little-legion.com/screen/folding2.jpg

Click to expand...

Do you have another NEO MVS to try with the monitor? If so is this Folding/Rollover occurring? If not you could try my suggestion below before looking to work on the monitor.

Are you running the RGB from the board direct to the monitor or going through a Supergun? This could possibly be a Sync issue (Connection "P" Solder side/bottom of JAMMA connector), as a standard video-signal has a Vpp of 0.7Vpp for being processed by the TV or Monitor. You could try coming out of the SYNC into a 220uF Capacitor + side then out on the - side of the Capacitor into a voltage divider (see below) then to either the monitor if you are going direct, or into the Supergun, this would be a test. The idea hear is to get the SYNC output stable and a normal voltage level.

A Voltage Divided is 2 resistors that work together to reduce the level of voltage. Normally the 1st resistor in this case would be wired to the negative side of the capacitor I mentioned above then the other side of this resistor is then wired to both the Monitor/Supergun and the 2nd resistor, the other side of the 2nd resistor is then wired to ground. In order to get the values need for the resistors we need to know what the voltage is on the Sync line.



Hope this helps, let me know if you need more info or if I have misunderstood the issue your having.

No, I'm running this in a big red cab and unfortunately, I don't have another board to test this with.
I had a supergun years ago and don't recall this being an issue, but the cabinet monitor has been for a while.
Due to life, I wasn't able to do much work on these kinda things until recently, so I haven't tried to fix it until now.