HP Vectra VL5 4 Supplementary Manual page 46

3 Troubleshooting and Repair
Power-On Self-Tests (POST)
Message
No message, system "hangs" after
POST
Other
48
Corrective Action and/or Explanation
Check that cache memory and main memory are correctly
set in their sockets.
An error message may be displayed and the PC may "hang"
for 20 seconds and then beep. The POST is probably
checking for a mass storage device which it cannot find and
the PC is in Timeout Mode. After Timeout, run Setup to
check the configuration.