Editing Sinclair QL Microdrive Troubleshooting Guide (section)

== Symptom tables ==

These are the Service Manual's Microdrive fault tables. Where a component is given as "X(Y)", X is the MDV1 reference and Y the MDV2 equivalent.<ref name="sm" />

{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''Microdrive symptom to remedy'''
! Symptom !! Remedy
|-
| Screen displays "Put a blank tape in MDV1 (MDV2)" even when a tape is present || 1. Check/replace TR7 (TR6). 2. Replace IC30 (IC29).
|-
| Screen displays "Failed microdrive test" || 1. Check for a write-protect tab on the cartridge. 2. Check headboard connector HBC1 (2). 3. Check the microswitch. 4. Check/adjust the motor. 5. Check R35 (R34), R37 (R36), C16 (C15), C18 (C17). 6. Renew IC30 (IC29). 7. Renew IC23. 8. Renew IC22.
|-
| Microdrive does not operate when selected || 1. Check TR7 (TR6), TR5 (TR4). 2. Check the motor. 3. Check the mechanics. 4. Check HBC1 (2).
|-
| Tight cartridge tape · noisy operation · fails to format · jammed tape · damaged cartridges · microdrive incompatibility || Mechanical: (a) weak clamp spring — listen for clicks/crunching; (b) faulty or maladjusted rollers; (c) adjust the motor. If the motor has overheated, check for a buckled baseplate and renew the complete unit.
|-
| Head failure || Renew the complete Microdrive unit
|-
| LED failure || Renew the LED (it is push-fitted)
|-
| Unreliable loading/saving, machine locking up || Check the modification state. 1. Renew IC30 (IC29). 2. Renew IC23. 3. Check motor position and roller.
|-
| Continuous running of MDV1 (MDV2) || Renew TR7 (TR6)
|-
| Microdrives do not activate at all || Renew IC23 (ZX8302)
|-
| Erase function not working || 1. Check TR3, D28. 2. Renew IC23.
|-
| MDV1 (2) does not run || Check TR7 (TR6), TR5 (TR4)
|}