Service manual

134 6
Digital Control Troubleshooting
INTRODUCTION
INTRODUCTION
Use this procedure only if you have followed the procedures in the Troubleshooting
chapter, and believe the problem to be in the digital control group. This procedure is
designed to let you identify the bad assembly within the digital control group in the shortest
possible time. Whenever an assembly is replaced in this procedure, refer to the Table of
Related Service Procedures in the Post-Repair Procedures chapter in this manual.
Figure 6-1 shows the digital control group in simplified block diagram form. The following
assemblies make up the digital control group:
• A1 CPU
• A30 Front Keyboard
• A32 I-BASIC Interface
• A34 EXT I/O Interface
• A51 GSP
• A52 LCD (Liquid Crystal Display)
• A53 FDD