Monitor/Board Sync issue?

[daskrabs]

Ok, so I'm just trying to test a Neo Geo 6-slot board. Looking for base functionality. I have a Pentranic CH-288 monitor and the Happ SNK PSU (here). I'm 90% sure I don't need an isolation transformer w/ this monitor, and I'm not using a noise filter. I don't have one. That's all I have hooked up.

I have the 9-pin power molex connected to the Neo harness. I have the 4-pin power switch molex lines crossed 1-3 and 2-4 so the PSU will turn on (I haven't wired the power switch in yet), and I have the 6-pin video cable from the monitor wired to the Neo harness as such: I have R to R, G to G, B to B, Ground to Ground, and Hsync to Sync. Supposedly my chassis supports composite sync over Hsync.

I get this:




I had this monitor hooked up to a PC via ArcadeVGA earlier tonight, and it was fine. I'm thinking either it's a sync issue on the board, or the fact that I have no noise filter is messing up the sync. Thoughts?

[daskrabs]

I found a thread relating to the topic, and traced the circuit from Pin P (sync) to 126 of LSPC-A0. All good. The 2 resistors measure out fine as well. I'm starting to run out of ideas? Can anyone suggest anything?

Here's a diagram of my setup:




Am I missing anything?

[grantspain]

looks like the video ground is missing
do you have some pics of the wiring to the monitor and to the jamma edge connector?

[qrz]

looking at the schematic ( http://arcarc.xmission.com/PDF_Monitors/Pentranic%20CH-288%20Switchable.pdf )

there is a switch ( j16) that should be open
and a jumper (j45) that should be closed for auto sync polarity .
Horiz and vert sync leads may be tied common

pic shows no sync lock


SMPS - no isolation xformer required

[daskrabs]

I don't see any switches. Can you point them out?

[daskrabs]