Computer host lights are not lit

Power supply fault can be caused by AC power supply circuit breaker, AC power supply voltage abnormality, microcomputer power failure or short circuit phenomenon in the host. Power supply failure is not necessarily the main engine damage caused by AC power supply voltage anomalies (overpressure or undervoltage), the host power supply no-load and the machine has short circuit phenomenon, the host power supply inside the protection circuit to start, automatically cut off the power output to protect the equipment inside the host.

1. Power supply system failure, first check the AC power supply is connected to the host.

2. Confirm AC power supply access to the host, close the ear to the switching power supply, a short time to turn on the power switch and pay attention to Xin, if you hear the internal issue of the power supply "squeak squeak ..." of the noise, indicating that the power supply in the "self-protection" working state, the reason is the AC power supply is not normal or the Causes the protection circuitry inside the power supply to start. Follow the steps below to check for processing:

(1) First use the multimeter AC voltage 250V block to check the AC power supply voltage of the main plug if the AC voltage is over 240V or less than 150V, the overpressure and Undervoltage protection circuit in the host power supply will be started, stop the power supply to the equipment, and should be replaced by a regulated power supply or a UPS power supply for the host.

(2) If the AC power supply voltage is normal, unplug each of the mainframe interface card and other equipment power cord, signal line, and then power test machine. such as the removal of a device when the host power recovery work, it is just pulled out of the equipment damaged or improper installation led to short-circuit, the power supply in the short circuit protection circuit to start, to stop the power of the machine equipment.

(3) If the power cord is removed from all devices, the power supply is still in no output state, which indicates a power failure.

Overhaul the power supply should be connected to at least one load (such as optical drive or hard disk), such as no-load connected to the microcomputer power supply, microcomputer power no-load protection circuit will start, stop output.

3. If the host power supply is not working, please check the host power switch installed in the chassis front panel of the main engine is normal, such as power switch intact, is generally a power failure.