Good controller to get for TGM?

Are you sure the TGM board is fine? Did you plug the JAMMA edge in backwards? If so you may have blown it up. Possibly not but post photos and I can help you (or contact me on some kind of messenger).

 

I'm pretty sure it's plugged in right. Here's a couple pictures of it.

 

What exactly is not working? Not getting an image, I assume?
What are you plugging the SCART cable into? Remember, there are two different SCART standards between Europe and Japan (JP21), and if you're using an XRGB or similar, it's most likely designed for the Japanese JP21 standard, while most superguns would use the normal European pinout.

Btw, I'm 100% certain TGM can survive being plugged in backwards.... don't ask how I know

 

Basically, yeah. Nothing is showing up on the TV. I'm using a SCART to Composite converter I bought off of Amazon.

 

"Scart to composite converter"? Sounds like your issue right there, if it doesn't anctually encode the RGB signal to composite.

SCART is designed to carry multiple types of signals, and one of the pins is designed for a composite video signal. So what your adapter probably does is just taking the composite pin of the SCART cable, and wiring it to an RCA plug on the other side, ignoring the RGB output from the arcade board altogether (though it's probably trying to display its sync signal as if it were a full composite signal).

Where do you live? If you're North American, an encoder to S-video or Component should work fine. If you're European, you should be able to plug the SCART plug into mostly any TV.

 

I'm American, but the problem with S-video or Component would be that the TV i play on is a really old CRT, and Composite is the only input it takes...

 

Converting RGB to composite is bound be be just as expensive as the other two, so I'm not sure I'd waste my money on that

 

Yup. The problem is definitely the type of cable. I remember making the same mistake when I tried to hook it up to a TV that couldn't handle it. So I'd say your options are to either get a signal converter or get a TV/monitor that can handle an RGB analogue signal such as VGA or BNC (I personally use BNC for my main monitor and VGA for my capture card.)

A cheap solution could be to buy a Sync Strike and an old CRT monitor off of ebay.

 

FYI if you mean a PC CRT monitor that will not work. Most PC CRTs don't support anything below 31k (640x480 progressive).