I recently purchased a TRS-80 Color Computer model 1 on ebay and have a few questions I'm hoping someone will be able to answer. The unit is an early model with the chicklet keyboard and badge on the left. Cosmetically it is close to near mint condition. However, when I turn it on there are vertical lines in the picture. My Color Computer model 2 does not have these lines. I also noticed that the colors appear washed out on the model 1 as opposed to my model 2. Is this normal for an early model 1, or are some capacitors possibly starting to fail? I also noticed that there is a noticeable buzz coming from the power supply, is that normal? My model 2 does not have this buzz. There is also a loose solder connection on the RF input jack, as when I move the RF cable the picture flickers. Should I just send the unit back for a refund?
First of all, you describe the image, but you never say it actually works. This assumes you are just talking about the crappy RF output.
The CoCo 2 RF design was better, though it isn't without it's share of potential problems.
Even if you clean up the video a little by changing capacitors, I doubt it will be as good as the CoCo 2 RF out.
The flicker is definitely a bad connection or bad cable.
Your best bet is to install a composite mod.
I don't remember a buzz from any of the CoCo 1s I've owned unless I put my ear close to it.
If it's loud, then there's probably an issue with it. Otherwise, it's probably normal.
It's tougher to find a CoCo 1 in near perfect condition than operating, so take that into consideration if you plan to return it.
If it has Extended Color BASIC, I'd probably keep it. Adding ECB to a machine will cost you a few bucks.
Personally, the later CoCo 1s and Earlier CoCo 2s are the best machines to mod or repair because of the number of socketed components and RAM support on the motherboard.
A pristine early CoCo 1 (especially 4K) or the "Tandy CoCo 2" with upper and lower case are probably the hardest machines to find up for sale.
Edited by JamesD, Wed Oct 3, 2018 12:01 PM.