In this video I present the CP400 Color II, a TRS-80 color computer 2 clone made in Brazil and the first computer I learned programming in BASIC and played games! It was bought as "for parts" and in this video I am going to show how to diagnose and fix it!
Summary:
00:00 - Intro
00:22 - The CP400 color II
01:08 - Cartridge door and connectors
01:49 - Same gift twice, 40 years apart!
02:33 - Looking inside the machine
06:21 - Is that a mod?
07:33 - The power supply
11:36 - Monitor port
13:27 - First power on
21:59 - A look at what we want to measure
26:30 - We have green video!
27:41 - Probing the circuit
32:25 - The original coco2 technical reference manual
36:36 - Probing the DRAM
38:55 - Replacing the DRAM
42:35 - RAM check
45:12 - Soldering back and fixing a track
48:23 - Trying the system
49:31 - Comparing PSUs
50:07 - A new PSU?
51:19 - Closing
Links:
https://en.wikipedia.org/wiki/Prol%C3%B3gica_CP-400
https://github.com/FabioNMI/archive/tree/main/manuals/CoCo