Service manual

Testing 7
Refer to Chapter 3 of this guide for information on creating the special
diagnostic keys on the diskette and tape.
1.3.1 System Exerciser Diagnostic Commands
Table 1–2 lists the system exerciser diagnostic commands. When running
TEST 0 or TEST 101, the exerciser automatically stops after about 5
minutes and the HALT message (06 HLT INST) is displayed. This HALT
message is normal for these two tests.
1.3.2 System Exerciser Codes
The system exerciser displays the status of the devices on the screen as
the exerciser is running. Any errors found are displayed in the exerciser
display. When examining the exerciser display, a question mark (?) in the
far left column indicates a soft error, double question marks (??) indicate
a hard error, and the absence of question marks usually indicates success.
There may be times when there are no question marks, but a drive may
not be listed in the display (for example, an unplugged power cable). In
these instances you need to be familiar with the codes of all devices so
that when you examine the display, you know if a specific drive or device
is listed, and if the drive or device has a fault.
The system exerciser codes are located in Appendix C.