Power-On Self-Test Sequence - IBM PC CONVERTIBLE Technical Reference

Power-On Self-Test Sequence
Description
Error Indication
Processor test: Verifies processor System power off.
operation.
System ROM checksum test: I-long and I-short
Verifies system ROM. beep, then system
power off.
Real-iime clock RAM test: Verifies
l-iong and I-short
the clock. If contents have been beep, then system
altered, RAM is cleared and power off.
system profile defaults are loaded.
Power source and battery check:
3-short beeps, then
Checks for external power. If no
system power off.
external power, checks for good
battery.
Base 8K RAM test: Validates first I-long and I-short
8K of RAM and clears it to zero. beep, then system
power off.
Internal modem power on: Checks
for internal modem presence and
applies power to it ifpresent. See
Figure 1-2 on page 1-9 for
additional information.
Figure 1-1 (Part 1 of7). Power-on Self-Test Sequence
1-2 Power-On Self-Test (POST)