Table of Contents
Internal Flexible
Disc Drive LED
Printer
Self Test LED
Printer and Disc Drive LEOs
Internal Flexible Disc Drive/Controller Card
9020 Diagnostics 5-11
Internal Fixed
Disc Drive LED
The first part of the self test checks the drive, the drive board, and the controller card. The LED on
the front of the drive indicates successful completion when it turns on.
The second part of the test requires that an initialized disc be stored in the drive. This part of the test
thoroughly checks the drive. If the test passes, the LED on the controller card turns on and off once.
With the right cosmetic door open, the controller card LED is visible through the upper hole in the
110 cover plate.
Internal Fixed Disc Drive/Controller Assembly
An LED on the drive is visible through the air vents under the keyboard. If this LED turns on, the
controller assembly has successfully passed self test.
If the drive LED goes on, indicating the drive is being accessed, but the controller assembly LED
fails to go off, a bad drive is indicated. With the right cosmetic door open, the controller assembly
LED is visible through the middle hole in the
110 cover plate.
Bootstrap Loader Card
The LED on the bootstrap loader card is visible through the middle hole in the I/O cover plate with
the right cosmetic door open. If the LED turns on and then off, the bootstrap loader code has been
properly downloaded to the system RAM. If the LED fails to turn off, the code has not loaded
properly.
Self Test Supervisory Code (STSC)
The STSC runs automatically after the module self tests on powerup. STSC verifies the integrity of
the internal I/O bus, tests the interfaces on all of the internal modules, retests mapped-out memory
blocks that previously failed the memory controller test, and reports the blocks that fail the retest.
The code issues a message to the user in case of a failure.
The modules tested by the STSC are:
• Internal
110 bus
• Printer
• Keyboard
• Display interface module (9020B or 9020C)
• Alpha/interface and graphics/digital video boards (9020A)
• Internal flexible disc drive and controller card
• Internal fixed disc drive and controller assembly
Table of Contents
Troubleshooting
