IBM 5110 Maintenance Information Manual
The IBM 5110 Maintenance Information Manual, order number SY31-0550-2 (February 1979), is IBM's field service manual for the IBM 5110 Computing System. 277 pages.
What it contains
[edit | edit source]- Locations (section 2) — the power supply PC board, the AC box with its line filter, AC capacitors C1 and C2 and fuse F1, removals and replacements, the Y1 socket pin assignments with the Y1 cable pin to A1 board pin mapping, and the DC rail tolerance table for loaded and unloaded conditions (272), followed by AC voltage distribution (273) and DC voltage distribution (274).
- Theory (section 3) — "Power Supply PC Board" and "Power Supply Protection": the supply is a small, high power, high frequency transistor switching regulator (TSR) developing +5 V, −5 V, +8.5 V, +12 V and −12 V, with stated overvoltage, undervoltage and overcurrent trip conditions and a five-second minimum off time after an automatic shutdown.
- Maintenance analysis procedures, error codes and probe points.
What it does not contain
[edit | edit source]No capacitance values, and no component-level parts list for the power supply. The DC supply is documented as a sealed assembly with numbered output terminals. Its internal circuit is not published in this manual or in the companion IBM 5110 System Logic Manual.
Download the IBM 5110 Maintenance Information Manual here: IBM 5110 Maintenance Information Manual SY31-0550-2.pdf