HP Compaq 100 Reference Manual page 60

Problem: The screen is blank.
Press the spacebar to see if any power management feature has blanked
the screen to save power.
If the AC power indicator is not on, check the electrical outlet, the plugs and
power cords.
If you are using a battery pack, make sure it has a charge remaining, and
that it is installed correctly.
Check the brightness and contrast controls for your display.
Reset the notebook by pressing the [Ctrl]+[Alt]+[Delete] keys.
Turn the notebook off, wait a few seconds, and then turn the notebook back
on.
Problem: Bad pixels appear on the display screen.
Because of limitations of the LCD technology, bad pixels may appear on the
screen. The inspection standard generally agreed in the LCD industry
allows a maximum of 8 bad pixels on an unit.
Problem: The diskette drive cannot read or write a diskette.
The diskette is not yet formatted, or could be corrupted.
If you can't write to a diskette, the diskette may be write-protected. Check to
ensure that the write-protect tab covers the detection hole.
If you can't write to a diskette, the diskette may be full. Use another
diskette.
Problem: The message "non-system disk" or "disk error" appears on the
screen after you turn on the system.
You may have inserted a non-bootable diskette in the diskette drive.
Remove the diskette.
Check the SCU program to ensure that the drive types are correctly
identified.
If this message is issued when you attempt to boot from your hard disk
drive, insert a bootable diskette and check the integrity of your hard disk
drive.
Problem: The date and/or time is incorrect.
Correct the date and time using the SCU program or your operating system.
If the date and time are still incorrect, contact your Compaq authorized
service provider to replace the RTC battry.
B-2 Troubleshooting