TRS-80 Model 16B Capacitor Replacement Guide
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No parts list for the TRS-80 Model 16B has been found: its service manual, which the Tandy 6000 manual refers to, is not available online.[1] Tandy did publish parts lists for the boards of the Model 16 that came before it and the Tandy 6000 that followed, and these lists differ. Match the Tandy part number printed on each board in your machine to the tables below, then use the guide for the machine whose board it is. Where a board matches neither, read the values from the parts.
 | Unplug the machine before working on it. The power supply and the monitor hold high voltages; discharge the CRT as described in the CRT Discharge Procedure. |
Identify the 68000 boards
[edit | edit source]| Board | Tandy part no. | Electrolytics listed | Guide |
|---|---|---|---|
| Model 16 MC68000 CPU board | 8898000 | 20 x 100 µF 16 V radial (C27-C32, C36-C40, C42-C48, C51, C52) | TRS-80 Model 16 Capacitor Replacement Guide |
| Model 16 128K/256K memory board | 8898001 | None (0.1 µF decoupling only) | TRS-80 Model 16 Capacitor Replacement Guide |
| Tandy 6000 MC68000 CPU board | 8898855 | C54, C55 100 µF 16 V radial | TRS-80 Model 6000 Capacitor Replacement Guide |
| Tandy 6000 512K memory board | 8898854 | C1, C2 100 µF 16 V; C29, C49 100 µF 10 V axial; one unnumbered 1 µF 16 V | TRS-80 Model 6000 Capacitor Replacement Guide |
Sources: the Model 16 and Tandy 6000 parts lists.[2][3] Tandy's 16B manual gives 384 KB or 512 KB for the 16B's 68000 memory, so a 16B may carry a different memory board from either of these.[4]
Z80 side, power supply and monitor
[edit | edit source]| Assembly | Model 16 (part no.) | Tandy 6000 (part no.) | Parts list |
|---|---|---|---|
| Z80 boards | Separate CPU (8898020), floppy controller (8898019), 64K memory (8893498) and video (8898018) boards | One I/O processor board (8898423) and a video/keyboard board (8898022) | 6000 only |
| Power supply | 13 A supply, 8790040 | Astec AA11082, 8790047 | 6000 only |
| Monitor | CRT display 8898021 | TCE monitor board 8790614 | 6000 only |
Sources: Model 16 mechanical parts list and the 6000 parts lists.[2][5] If the labels in your 16B match the 6000's assemblies, the TRS-80 Model 6000 Capacitor Replacement Guide lists every electrolytic on them. Otherwise, the TRS-80 Model II Capacitor Replacement Guide shows the kind of circuits on the Z80 side, though its boards carry different part numbers.
Hard disk
[edit | edit source]The 15 MB built-in drive (six heads, 306 cylinders) has no capacitor list in any of the manuals used here.[4] The Tandy 6000 HD's drive of the same geometry, a Tandon TM503, has its own 38 W switching supply, model AA 11330, also without a list in the 6000 manual.[6]
Procedure
[edit | edit source]- Record each board's Tandy part number and revision before ordering parts.
- Work on one board at a time, and note each capacitor's polarity before removing it.
- Use an earthed wrist strap and mat: the trs-80.com notes stress that static damage is cumulative.[7]
- Afterwards, check that the machine boots without a boot error; the codes are on the TRS-80 Model 16B Troubleshooting Guide.
See also Capacitor Failure Symptoms.
Related pages
[edit | edit source]- TRS-80 Model 16B
- TRS-80 Model 16B General Maintenance
- TRS-80 Model 16B Troubleshooting Guide
- TRS-80 Model 16 Capacitor Replacement Guide
- TRS-80 Model 6000 Capacitor Replacement Guide
- TRS-80 Model II Capacitor Replacement Guide
References
[edit | edit source]- ↑ Tandy Computer Products, Service Manual, Tandy 6000/6000-HD, catalogue numbers 26-6021/2, 1985, hosted as File:Tandy 6000 Service Manual (26-6021, 26-6022, 1985).pdf. Section 3, p. 9.
- ↑ 2.0 2.1 Radio Shack, TRS-80 Model 16 Service Manual, catalogue numbers 26-6001/2, 1982, hosted as File:Radio Shack TRS-80 Model 16 Service Manual (26-6001, 26-6002, 1982).pdf. Section 5, "Parts Lists", pp. 61-73.
- ↑ Service Manual, Tandy 6000/6000-HD (1985), parts lists for the CPU board (pp. 93-95) and memory board (pp. 114-115).
- ↑ 4.0 4.1 Radio Shack, TRS-80 Model 16B Built-in Hard Disk System Manual, 1983, hosted as File:Radio Shack TRS-80 Model 16B Built-in Hard Disk System Manual (1983).pdf. Appendix D, "Specifications", pp. 60-63.
- ↑ Service Manual, Tandy 6000/6000-HD (1985), Section 7 parts lists and Appendix A.
- ↑ Service Manual, Tandy 6000/6000-HD (1985), Section 7.10, "Hard Disk Controller", pp. 219-228.
- ↑ Ira Goldklang, "TRS-80 Troubleshooting Guide and Repair Q&A", Ira Goldklang's TRS-80 Revived Site (retrieved 2026-10-21). "All Models" section, "Static".