Hi everyone!
First time posting here. Back in the 80's I owned a Vic20, then a coco2 16, and later a C-64. In the early 90's I picked up a used amiga 500 from a friend which I used until my first PC (a Leading Edge 486). I've gotten into retro computing but had to reacquire the hardware since I lost all my originals to a surprise post-divorce garage cleanup. I've picked up (among other things) a Coco2 and more recently a Coco3. The Coco2 will only output black and white over the RF out. I've tried both channel 3 and 4 and also switched TVs but no luck. does anyone have a suggestion as to where to start diagnosing? I'm an electronics newbie but willing to get my hands dirty. Also, the Coco3 came with a bunch of cartridges of which only 2 worked. The rest either didn't boot at all or booted to a blank screen. I tried both Cocos with the exact same results. My suspicion is that the contacts are corroded but it's almost impossible to keep the cart open to clean the contacts. They are a terrible design, hard to insert into the machines as well. Does anyone know how to open them up safely to check them and clean the contacts?
Thanks all, any help is appreciated.
-Erik