TJBChris | TRS-80 Model 4: Installing And Testing A Serial I/O Card @TJBChris | Uploaded May 2021 | Updated October 2024, 6 hours ago.
I disassemble my project TRS-80 Model 4 computer to install a replacement serial I/O card. Then, after reassembling the computer, I test the card out using my Tandy 1000 SX as a second terminal. This video covers case removal, motherboard removal, installation of the card, re-installation of the motherboard, and reassembly of the case.

If you like to jump around, here's the index:
Intro (0:00)
Case Disassembly (0:56)
Whiskey Break (3:23)
Removing the shielding and motherboard (3:35)
The Missing Screws (5:34)
Installing the Serial Card (6:28)
System Reassembly (6:43)
Testing (10:04)
Outro And Next Steps (11:56)

I do these videos unscripted, so I apologize if the in-the-moment descriptions of things are a bit all-over-the-place. If you have any questions/comments about this video, you can find me in any of these fine locations:

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

Thanks for watching!