Solving Power Problems - HP EliteDesk 705 G5 Maintenance And Service Manual

System does not power on and the LEDs on the front of the computer are not flashing.
Cause

Solving power problems

Common causes and solutions for power problems are listed in the following table.
Power supply shuts down intermittently.
Cause
If equipped with a voltage selector, voltage selector switch on
rear of computer chassis (some models) not switched to correct
line voltage (115 V or 230 V).
Power supply will not turn on because of internal power supply
fault.
Computer powered off automatically and the Power LED flashes red two times, once every second, followed by a 2 s pause, and
the computer beeps two times. (Beeps stop after fifth iteration but LEDs continue flashing.)
Cause
Processor thermal protection activated:
A fan might be blocked or not turning.
OR
The heat sink is not properly attached to the processor.
Solution
1. If equipped with a voltage selector, check that the voltage
selector (located on the rear of the power supply) is set to
the appropriate voltage. Proper voltage setting depends on
your region.
2. Remove the expansion cards one at a time until the 5V_aux
light on the system board turns on.
3. Replace the system board.
OR
Press and hold the power button for less than 4 s. If the hard drive
LED does not turn on white then:
1. Check that the unit is plugged into a working AC outlet.
2. Open the access panel and check that the power button
cable is properly connected to the system board.
3. Check that the power supply cables are properly connected
to the system board.
4. Check to see if the 5V_aux light on the system board is
turned on. If it is turned on, then replace the power button
assembly.
5. If the 5V_aux light on the system board is off, then replace
the power supply.
6. Replace the system board.
Solution
Select the proper AC voltage using the selector switch.
Replace the power supply.
Solution
1. Make sure that the computer air vents are not blocked and
the processor cooling fan is running.
2. Open the access panel, press the power button, and see if
the processor fan (or other system fan) spins. If the fan does
not spin, make sure the fan cable is plugged onto the system
board header.
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