Power-On Self-Test - IBM 6150 Hardware Maintenance Manual

TNL SN20-9843 (03-27-87) to 75X0152 or 75X0166
Power-On Self-Test
2-6 Service Manual
The resident Power-On Self-Test (POST) programs are in Read-Only
Memory (ROM) modules on the processor board. These programs run
when the system unit is first powered on. When the resident POST
programs complete, additional POST programs load from the fixed disk or
from the diagnostic diskettes.
Numbers display on the
two-digit display
to track the progress of the POST
programs. Some tests may run so quickly that the numbers may not be
visible.
Note: The following chart is for "steady" numbers only. Flashing (about
one second) numbers are for software failures. See "Two-Digit Display
Codes During Diagnostic Programs" on page 2-18 for flashing numbers
during the diagnostic checkouts.
Number Test description
88 Displays for one second to provide a lamp test. If "88" is
displayed steady, the 32-bit processor has stopped.
OO,Oc If installed, this test resets the IBM Monochrome Display and
Printer Adapter.
01, lc Tests the ROM modules on the processor board.
02 Tests for correct communication between the 32-bit processor
and the system board.
03,3c Tests the memory controller on the processor board and the
system memory boards in slots C and D.
04,4c Tests the processor board.
05,5c Tests the processor board.
07,7c Tests the I/O channel controller on the system board.