Dell Inspiron 1420 (Mid 2007) - Manual (Page 109)

Troubleshooting
109
4 From the Windows desktop, click Start → All Programs →
Accessories → Notepad.
5 Type some characters on the internal keyboard and verify that they appear
on the display.
If the characters appear now, but did not with the external keyboard, you
may have a defective external keyboard. Contact Dell (see "Contacting
Dell" on page 166).
R UN THE KEYBOARD DIAGNOSTICS TESTS — Run the PC-AT Compatible
Keyboards tests in the Dell Diagnostics (see "Dell Diagnostics" on page 93).
If the tests indicate a defective external keyboard, contact Dell (see
"Contacting Dell" on page 166).
Unexpected characters
D ISABLE THE NUMERIC KEYPAD — Press <Num Lk> to disable the numeric
keypad if numbers are displayed instead of letters. Verify that the numbers
lock light is not lit.
Lockups and Software Problems
CAUTION:
Before you begin any of the procedures in this section, follow the
safety instructions in the Product Information Guide.
The computer does not start
C HECK THE AC ADAPTER — Ensure that the AC adapter is firmly connected to
the computer and to the electrical outlet.
The AC adapter shuts down when there is a fault. The green light turns off
when this happens. To bring it back on, disconnect the AC adapter from the
power source for 10 seconds, and then connect it back on.
The computer stops responding
NOTICE:
You might lose data if you are unable to perform an operating system
shutdown.
T URN THE COMPUTER OFF — If you are unable to get a response by pressing a
key on your keyboard or moving your mouse, press and hold the power button
for at least 8 to 10 seconds until the computer turns off, then restart your
computer.