.op M 1 SERVICE GUIDE Copyright 1984 by Morrow Designs, Incorporated 600 McCormick Street San Leandro, California 94577 All rights reserved. THŠ SERVICŠ PROCEDUREӠ DESCRIBE I THI DOCUMENԠ ARŠ TϠ B PERFORMEĠ ONL B AUTHORIZE MORRO DESIGNӠ DEALERSHIPS ONL QUALIFIE SERVIC PERSONNE SHAL PERFOR TH REPAIRS QUALIFI CATIOΠ MA٠ B OBTAINE B SATISFACTOR COMPLETIO OƠ MORRO DESIGNӠ SERVIC SEMINA. .fo (08/13/84) i M 1 Servic Guide T A B L E O F C O N T E N T S --------------------------------- .cp4  1. INTRODUCTION.............................................1 1 .cp4  2. TROUBLESHOOTING..........................................2 2 Flowchart................................................2- 2 .cp4  3. ROM DIAGNOSTICS..........................................3 1 .cp4  4. COVER REMOVAL............................................4 1 Removal.................................................4 1 Replacement.............................................4 1 .cp4  5. POWER SUPPLY.............................................5 1 Removal.................................................5 1 Replacement.............................................. 2 .cp4  6 DISK DRIVES.............................................6 1 Removal..................................................- 1 Replacement..............................................6- 3 .cp4  7 MOTHERBOARD.............................................7 1 Removal..................................................7- 1 Replacement..............................................7- 3 .CP4  8. THEORY OF OPERATION......................................8 1 Architecture.............................................8- 1 Disk Controller..........................................8- 1 .CP4 A. ERRO CODES..............................................A 1 Bio Leve Erro Codes...................................A 1 RO Leve Erro Codes....................................A 3 .CP4 B. MOTHERBOAR CONNECTORS...................................B 1 .CP4 C SCHEMATICS...............................................C 1 Motherboard..............................................C 1 .fo MD 11 Service Guide ii M 1 Servic Guide L I S T O F F I G U R E S ----------------------------- .cp3 4-1: MD 11 Cover Removal, Location of Screws................4- 1 .cp3 5-2: MD 11 Power Supply Removal (Location of Screws)........5- 1 .cp3 6-1: Side Mounting Screws, Hard Disk Drive..................6- 1 6-2: MD 11 Disk Drive Removal...............................6- 2 6-3: MD 11 Floppy Disk Drive Removal........................6 2 .cp3 7-1: Motherboard Screw Locations (Chassis Base).............7- 1 7-2: Motherboard Screw Locations (Rear Panel)...............7- 2 B-1: MD 11 Motherboard......................................B 1 B-2: Serial Port Pin Arrangement - Rear View................B 2 B-3: Factory Jumper Settings for JPA/B......................B- 4 B-4: JPA/B Settings for Modems..............................B 4 B5: Alternate JPA/B Settings for Modems....................B- 5 B-6: Factory Jumper Settings for JPC........................B 7 B-7: JPC Settings for Modems (Cables crisscrossing pins 2 an 3)....................B 7 B-8 Alternat JP Setting fo Modems......................B 8 .pa .fo (08/13/84) iii M 1 Servic Guide L I S T O F T A B L E S --------------------------- .cp3 A-1: BIOS Leve Erro Codes.................................A 1 A-2: ROM (Low-Level) Dis Operatio Erro Codes.............A 3 B-1: RS-232 Signal Descriptions.............................B 2 -2 JPA/JP Factor Settings...............................B 3 B-3: JPC Pinouts (Modem Setup)..............................B 6 B-4: DART Port Locations....................................B 8 B-5: MD-11 I/O Port Assignments.............................B 9 B-6: RS-422 Pin Connections.................................B 9 .pa  All rights reserved THŠ SERVICŠ