I purchased my first Colecovision on eBay a few days ago and got to pick it up yesterday. Seller was local to me, so bonus.
Anyway, after getting it home and cleaning a cartridge and the slot, it presents a fuzzy black and white image. Cleaned and tried other games with the same result. So out came the screwdriver so I could inspect the motherboard. The board went to the workshop and the plastic shell into warm and soapy water.
Well one issue jumped out pretty quick. The ceramic disc capacitor at location C70 had a broken leg and the area by the leg had a nice sooty coating. I dont know what caused it to die, but I suspect that its proximity to the cartrdge connector means it got crushed by an improperly inserted cartridge. If you open the cartridge door, C70 is at the right edge of where the cartridge sits.
So I remove the broken cap and check my Radio Shack capacitor assortment to no avail...worthless purchase so far. However I did have a piece of 2600 RF modulator left over from a mod that I hadnt thrown out yet. Glad I didnt because it had the exact capacitor I needed. A little bit of soldering later, my Colecovision is now working perfectly.
The moral of the story is to save capacitors, transistors, and other working bits from scrapped electronics. You never know when you'll need them.
Also, I tend to ramble, so please excuse me.
Sent from my SM-G925V using Tapatalk