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Main => Monitor/Video Forum => Topic started by: daskrabs on January 21, 2011, 09:05:51 am

Title: Monitor/Board Sync issue?
Post by: daskrabs on January 21, 2011, 09:05:51 am

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 (http://"http://www.happcontrols.com/powersupplies/80007200.htm")). 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:

(http://lh4.ggpht.com/_7v_oEyxezIE/TTejMRibChI/AAAAAAAABaw/6vSwDGgrgLY/s720/IMG_2713.JPG)


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?

Title: Re: Monitor/Board Sync issue?
Post by: daskrabs on January 24, 2011, 02:16:21 pm

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:

(http://lh6.ggpht.com/_7v_oEyxezIE/TT3O7K5EiXI/AAAAAAAABbQ/VH5qwKAUvPQ/s800/6slot.bmp.jpg)


Am I missing anything?

Title: Re: Monitor/Board Sync issue?
Post by: grantspain on January 24, 2011, 03:43:12 pm

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

Title: Re: Monitor/Board Sync issue?
Post by: qrz on January 24, 2011, 09:05:01 pm

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

Title: Re: Monitor/Board Sync issue?
Post by: daskrabs on January 24, 2011, 09:59:53 pm

(http://lh5.ggpht.com/_7v_oEyxezIE/TT48Ua19-WI/AAAAAAAABbY/_PHwdCrliKk/IMG_2719.JPG)

(http://lh6.ggpht.com/_7v_oEyxezIE/TT48VIGjL7I/AAAAAAAABbc/Kmh3_e9CoEc/s576/IMG_2724.JPG)

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

Title: Re: Monitor/Board Sync issue?
Post by: daskrabs on January 24, 2011, 10:01:54 pm

(http://lh6.ggpht.com/_7v_oEyxezIE/TT5RibKK12I/AAAAAAAABbk/EoEHQ-d_WUc/IMG_2725.JPG)

(http://lh5.ggpht.com/_7v_oEyxezIE/TT5Ripr4dbI/AAAAAAAABbo/7F_rQXuMaFk/IMG_2726.JPG)

(http://lh5.ggpht.com/_7v_oEyxezIE/TT5Ri_kff9I/AAAAAAAABbs/76ktNyYAkVk/IMG_2728.JPG)