Repairing The PDP-11/34 To Component Level

About the machine

The PDP-11/34 is a late 1970s minicomputer implemented in SSI TTL, low-density bipolar ROM and low-density MOS DRAM.

The disks in the PDP-11 are two 5Mb RL-01 removable cartridge drives.

The First RL-01 Fault

Symptom: RL-01 fault light on. Cause: Failed read amlifier chip, preventing servo pulses from reaching controller. Remedy: Replace failed amplifier chip.

The Second RL-01 Fault

Symptom: RL-01 fault light on. Cause: Failed voice-coil driver transistor, preventing head from being moved into tracks on disk. Remedy: Replace failed transistor.

The Control-Panel Fault

Symptom: PDP-11 fails when warmed up. Cause: Defective biploar PROM chip on control-panel card. Remedy: Replace failed chip.