Sinclair QL Service Manual

The QL Service Manual was HTML'ed by Juanjo Ruiz Leo (juanjoruizleo@terra.es).

Prepared by THORN (EMI) DATATECH LTD for SINCLAIR RESEARCH LTD
OCTOBER 1985
© Sinclair Research Ltd.
SERVICE MANUAL X-1204

List of Contents

• SECTION 1 SYSTEM DESCRIPTION
• SECTION 2 DISASSEMBLY/ASSEMBLY
• SECTION 3 SYSTEM TEST
• SECTION 4 FAULT DIAGNOSIS AND REPAIR
• Appendix A Known Bugs and their Remedies
• Appendix B User Hints
• Appendix C Mandatory Modifications
• Appendix D Microdrive Fault Finding
• SECTION 5 PARTS LISTS

List of Illustrations

• RS 232 Link
• Keyboard Matrix Interconnections
• QL Block Diagram
• QL Circuit Diagram (Issue 5)
• QL Circuit Diagram (Issue 6)
• Motor Location Jig
• Keyboard Format
• Head Chassis
• Issue 5 Board - Component Side Modification
• Issue 5 Board - Solder Side Modification
• Issue 6 Board - Solder Side Modification
• Microdrive Signals (100 kHz WRITE)
• Microdrive Signals (100 kHz READ)
• Microdrive Signals (100 kHz FORMAT READ)
• ULA 2G007 - Internal Circuit
• Printed Circuit Board (Issue 5) Component Layout
• Printed Circuit Board (Issue 6) Component Layout

History Sheet