Well it has been a number of years, but I recall having this problem with Toaster systems I used to fix. First, the clean connector suggestion is a great one. Do that, and if you still get the garbled output, there's a small potentiometer on the board which you can very slowly turn while watching the garbled output, which should adjust the garble out. Tigger I'm sure will remember what this pot is called, sorry I don't, I just remember firing up the jittery toaster, and if I didn't get a TNR (Toaster Not Responding) error, quitting the toaster. Then the output was garbled till I very gently adjusted that pot, usually about a tenth of a turn would do it. Then once I got it running, time to autohue it. Sometimes we had to autohue it a bunch of times. Newtek told us to do it a lot if we had to.
Back then, it wasn't 'next to nothing' to get Newtek to fix a Toaster, we had to gat an RMA for each one. It could go up to $600 depending on the problem! So we'd basically mix n match the bits of various Toasters till we had one with all three boards bad, then send it in for repairs. Once we got the new, known good board we'd either sell it whole as a refurbished board (we weren't unethical to call them 'new' when we knew they'd been overhauled, but some places, cough, AG, cough, were so..) or use its parts for repairing customer's units without the two to three week turnaround of sending it in to Newtek. Newtek were, however, very nice to deal with and I always liked calling them. Keep in mind that this was before everyone had a Mac with Final Cut Pro and firewire digital camcorders. The Toaster was still a very common profesional system. Lots of places made their living with the Toaster for a long time :-)
I remember lots of A2000s full of TBC IVs or Kitchen Syncs. Very cool gear back in the day!
Memories...