Tandy Color Computer 2 Ram upgrade and strange activity

[VERAULT]

So I installed the Composite video audio board I printed some pcbs of. Its a clone of the mid 1980s Mark Data Products UVD (Universal video Driver) Board. IT just has 5 leads you clip to various locations depending on your Coco 1 or 2 model and thats it. I had it in and working in 5 minutes after I built it.

The intructions were pretty easy to follow. https://colorcomputerarchive.com/repo/Documents/Manuals/Hardware/Universal Video Driver (Mark Data Products).pdf
Its a solderless non destructive mod so It can be pulled in a heartbeat if you choose to get rid of it for something else.





I plan on building another for my Coco 1 next. And that makes 2 less machines I own relying on RF for sound and video!!!

 

[mrclassicman]

I know it is a little late to the post but I have also built the Clone UVD board and installed it on an "F" board model 1 Coco. Unfortunately it has not turned out so well for me. It looked extremely promising at first with very sharp crisp colors only no horizontal sync. Plus after approximately 20 seconds the display goes blank. I was thinking about the output over driving the monitors input so I pull the board checked each resistor and capacitor to insure proper value.
Everything checked out. I also confirmed the ground and 5v supply hook up and it was spot on. Would you be able to offer some idea as to where I should go from here?

 

[VERAULT]

Im sorry I have never seen that particular fault. If it keeps failing after 20 seconds, Id assume either a bad or weak connection somewhere or one of your transistors is failing/failed.

 

[mrclassicman]

Im sorry I have never seen that particular fault. If it keeps failing after 20 seconds, Id assume either a bad or weak connection somewhere or one of your transistors is failing/failed.

Thank you for the input, I really appreciate it. I have a few things to check out and another monitor to try so all is not lost yet! lol The transistor is a really good lead too!

Terry