Uploaded March 2022 | Updated September 2026, 3 weeks ago
I picked up a TRS-80 Model I with Expansion Interface and a disk-less 16K TRS-80 Model III. In this video, I look over the machines and start to dive deeper into the Model III. The power cord, which had been cut on the III, gets replaced. I test out the power supply, and with the help of the oscilloscope, I start to diagnose issues powering the system up. Prior to shooting this video, I did a basic clean-up and prep of these machines.
Music: Night on the Town by TrackTribe
(Taken from the YouTube Audio Library)
Chapters:
Intro & A Look at the Model III (0:00)
A Look At The Model I (1:34)
The Model III - Condition (3:23)
Disassembling the Model III (5:09)
First Look: Power Supply and Video Driver Board (6:28)
Looking At The Motherboard (7:20)
Installing The New Power Cable (8:39)
First Power-Up Attempt (10:42)
Contrast and Brightness Control Rehab (12:14)
Power Supply Voltage Check (15:54)
Do the Contrast and Brightness Pots Work? (18:14)
Hunting for Video Signals Using the Oscilloscope (21:10)
A Little Pop...And A Burning Smell (23:58)
Recap and Next Steps (25:03)
Outro (26:07)
I do these videos unscripted, so I apologize if the in-the-moment descriptions of things are a bit scattered. If you have any questions/comments about this video, you can find me in any of these fine locations:
The Tandy Discord Server
The CoCoTALK! Discord Server
The TRS-80 Color Computer (CoCo) group on Facebook
The CoCo Crew Podcast group on Facebook
On the Vintage Computer Forums (vcfed.org)
The TRS-80 Models I-4/4P Group on Facebook
Tandy / Radio Shack Model II /12 / 16 / 16B / 6000 Owner's Group on Facebook
Twitter (I'm TJBChris there, too...)
Thanks for watching!
I picked up a TRS-80 Model I with Expansion Interface and a disk-less 16K TRS-80 Model III. In this video, I look over the machines and start to dive deeper into the Model III. The power cord, which had been cut on the III, gets replaced. I test out the power supply, and with the help of the oscilloscope, I start to diagnose issues powering the system up. Prior to shooting this video, I did a basic clean-up and prep of these machines.
Music: Night on the Town by TrackTribe
(Taken from the YouTube Audio Library)
Chapters:
Intro & A Look at the Model III (0:00)
A Look At The Model I (1:34)
The Model III - Condition (3:23)
Disassembling the Model III (5:09)
First Look: Power Supply and Video Driver Board (6:28)
Looking At The Motherboard (7:20)
Installing The New Power Cable (8:39)
First Power-Up Attempt (10:42)
Contrast and Brightness Control Rehab (12:14)
Power Supply Voltage Check (15:54)
Do the Contrast and Brightness Pots Work? (18:14)
Hunting for Video Signals Using the Oscilloscope (21:10)
A Little Pop...And A Burning Smell (23:58)
Recap and Next Steps (25:03)
Outro (26:07)
I do these videos unscripted, so I apologize if the in-the-moment descriptions of things are a bit scattered. If you have any questions/comments about this video, you can find me in any of these fine locations:
The Tandy Discord Server
The CoCoTALK! Discord Server
The TRS-80 Color Computer (CoCo) group on Facebook
The CoCo Crew Podcast group on Facebook
On the Vintage Computer Forums (vcfed.org)
The TRS-80 Models I-4/4P Group on Facebook
Tandy / Radio Shack Model II /12 / 16 / 16B / 6000 Owner's Group on Facebook
Twitter (I'm TJBChris there, too...)
Thanks for watching!
