ArcadeVGA & Video Amp setup issue

[witchfinder]

I'm working on a MAME cabinet project (going into an old DECO Cassette System cab) and have just got around to connecting the PC to the Arcade cab monitor for the first time, but am not getting a picture on it.

I'm using an AGP ArcadeVGA card which is then plugged into an Ultimarc VGA Video Amp, which is then connected to the monitor inputs.


Things I know:

1. The output from the ArcadeVGA card to a regular PC monitor works.

2. The Arcade monitor worked a few months ago when I first got the cab. It has been sitting dormant for quite a while, but I can definitely hear it powering up and down.


Things I don't know:

1. I have no idea if the Ultimarc Video Amp works or not - is there any way to test this?

2. I do not know if the arcade monitor even needs the Video Amp - it's quite an obscure monitor and I couldn't find any info about what voltage the inputs would need, so I thought the safest option would be to use an Amp as presumably if it didn't need it nothing bad would happen. However is it possible I could have overloaded something by using the amp?

3. The 110v arcade monitor is currently connected direct to the mains through a stepdown isolation transformer. Originally it was wired to the mains connectors of the cabinet (before I took them out) via an on/off switch, and it also has a degauss switch. Neither the on/off or degauss switch are wired into the mains supply currently - could this be the source of my problem?


Any ideas on how I can get to the bottom of this? Is there any way I can try and send something into the arcade monitor to see if it even works anymore? Something I could connect to the RGB, Ground and Sync wires that would just send a test signal? If I can confirm the monitor works then at least I know the issue must be with either the Video Amp or the arcade monitor output of the ArcadeVGA card.

Any help or advice would be appreciated as I'm currently looking at a beautifully restored cabinet that is completely useless! 

I can upload photos of anything that may help diagnose the issue, if necessary...

Thanks!

[FlatEarth]

Try building something like this:
http://www.therealbobroberts.net/rgb.html

You can test your monitor independently of your computer video signal.

BTW, I am using an ArcadeVGA and a JPac (which has a video amp in it) to drive my arcade monitor, and it works fine.

[witchfinder]

Sorry for bumping the thread (and not replying sooner) but thanks for the link, that was really useful. I put together a simplistic version of that unit - one button fed by a 4.5v DC power supply - and it has helped me prove that the monitor is fine (phew!) so I can now hopefully get a replacement Video amp and/or Arcade VGA card.

Thanks again! 

[Osirus23]

Have you tried connecting the monitor to the card without using the amp?

[witchfinder]

It turned out I was being a dumbass and powering up the PC with both monitors attached - I didn't know you should only attach the aracde monitor when powering everything up! 

So it actually all works fine and I've wasted 3 weeks trying to figure out what was wrong - DOH!