Compaq dc7700 - Convertible Minitower PC Service & Reference Manual page 224

Troubleshooting Without Diagnostics
Solving Power Supply Problems (Continued)
Problem
Power LED flashes Red, four
times, once every second,
followed by a two second
pause, and the computer
beeps four times. Beeps
continue for five iterations
after which the LED flashes
will continue until the
problem is resolved.
D–6
Cause
Power failure (power
supply is overloaded).
433612-001
Solution
1. Check that the voltage selector
(some models), is set to the
appropriate voltage. Proper
voltage depends on the region.
2. Open the hood and ensure the
4- or 6-wire power supply cable
is seated into the connector on
the system board.
3. Check if a device is causing the
problem by removing ALL
attached devices (such as hard,
diskette or optical drives, and
expansion cards). Power on the
system. If the system enters the
POST, then power off and
replace one device at a time
and repeat this procedure until
failure occurs. Replace the
device causing the failure.
Continue adding devices one at
a time to ensure all devices are
functioning properly.
4. Replace the power supply.
5. Replace the system board.
Service Reference Guide, dc7700