Thanks to some lovley people on the internet I have works around the issue with my Ms2930 and it’s now back to full working order again! The problem? The third dip switch on the remote board is faulty. Why did this cause the image to be dark? Well, this switch is the input selector for the monitor where you can choose between the standard CGA socked connection and the D-Sub VGA connection. The VGA option / connector expects a stronger video signal than the CGA one so it was displaying a dark image. BUT if I had it set to the standard CGA connector WHY did it think it was getting a VGA picture?
Here’s what the remote board looks like (not my picture, found it on THIS SITE) and his pic is MILES better than the photo I could take so it illustrates the components perfectly. The dip switches in question are circled on the right.
Now, since I’ve had the cab this switch has been set to “on” which would indicate that it’s passing video through the VGA D-Sub. However, that’s never been the case. I’ve always had the monitor hooked up to the standard connector.
Because this switch is so hard to change (let alone view) with the control panel attached to the cab and not having seen any pictures of it I had always assumed that, because my system worked, that “up” was “off” and “down” was on. This actually didn’t matter to much for 15Khz boards as the res was essentially changed with sw1 which could be in either position for 15Khz games. The pic below shows you what I mean by hard to get to (taken before cleaning the CP).
After Studying the great picture above it seems my assumptions were clearly wrong. “up” is “on” and down is “off” so it looks like SW3 had been knocked and was stuck in the VGA position. All I had to do to”fix” the issue was use a screwdriver to ensure that , when I moved the switch, it connected underneeth and switched modes. Prior to this the plastic bit was moving but nothing underneath was changing position.
So I know I have a dead / Faulty SW3 but it’s now stuck in the correct position for day to day operation and I really dont have the time to dismantle and fix at the moment so I’m leaving it as-is. I’ll probably get a replacement Dip switch bank but, for now. I can game once again (well, at least via the CGA connector).