Compaq Compaq Evo Desktop, 177620-006 manual Solving Power Supply Problems

Troubleshooting Without Diagnostics

Solving Power Supply Problems

Solving Power Supply Problems

Problem Cause Solution

Computer won’t turn on (Power LED on front of computer not on).

Computer is not connected to an external power source.

Connect to an external power source.

Cables to the external	Ensure that cables connecting the
power source are	computer to the external power
unplugged.	source are plugged in properly
	and the wall outlet is active.
Power switch not	Plug the power switch cable into
connected to the	the system board.
system board
(supported on select
models only).

Power line selector switch on rear of computer chassis not switched to correct line voltage (115V or 230V) (some models).

Select the proper AC voltage using the slide switch.

	Wall outlet is defective.	Test the outlet by connecting a
		different electrical device to the
		outlet.
Power LED flashes Red or	Power supply	Unplug computer from AC power.
Yellow every 2 seconds on	overloaded or short	Unplug internal power cables from
most models.	was detected.	all devices and unplug all PCI
		cards. Reconnect devices one at
		a time and turn power on to identify
		the cause.
	Diskette drive power	When installing power cable to
	cable not properly	diskette drive, ensure that all 4 pins
	connected.	on the drive are connected to the
		power cable connector.

2–6 Troubleshooting Guide