Can you test this and see if it does anything? Bash the desk under your Amiga with your hand or knee, around the area where the accelerator is. If it crashes it's probably the connection between the Amiga and accelerator. When we get a problem like this, this is what to do: Get a rubber eraser and rub down the expansion edge of the A1200 so the metal looks nice and shiny again. Then carefully use a sewing needle to push each of the metal wire "teeth" inside the accelerator's expansion connector so that they're closer to each other, and "bite" down better on the edge. Over the years these wire teeth seem to receed a bit so they're not always holding onto the Amiga as well as they once did, and only need to be pushed back to make a better connection again.
You can use duct tape if you want but I think my way is a little less messy. :p
The other problem could be the capacitors, once they start to go you will get all sorts of problems. First come the random crashes, I think caused by timing issues, and eventually you notice one of the audio channels going, then one day it might start to smell funny... don't let it get this far!
All A1200s need their capacitors replaced if they haven't had it done yet. Same with A600s, and soon CD32s will all start failing too, and those have a mega beasty capacitor which Commodore put in backwards which definitely needs replacing.
