The computer monitor is not lit up, and there is no sound of starting the alarm drop

1. If it is a CRT (picture tube display), then.

1) CRT automatic shutdown (CRT's indicator lights are off), the problem is:

1. The high-voltage control circuit is out of control, and the voltage rises, which stops the oscillation circuit;

2. The counter-path capacitance capacity is unstable;

3. Voltage regulator circuit failure, such as rectifier diode, filter capacitor breakdown;

4. The thermal stability of the switch tube decreases.

b) CRT auto shutdown (CRT power indicator flashing), the problem is:

1. Poor voltage stabilizing circuit, generally due to damage to the integrated block, open circuit of resistor or potentiometer;

2. The capacitor of the oscillation circuit leakage;

3. High-voltage protection, generally:

a. The output power supply voltage is too high, so that the anode high voltage exceeds the rated value;

b. The scanning frequency is too low;

Second, if it is LCD (liquid crystal display), then.

a) LCD auto shutdown (LCD indicators are off), the problem is:

The rectifier diode or filter capacitor of the LCD high-voltage rectifier power supply is damaged;

b) LCD auto shutdown (LCD's power indicator flashes), the problem is:

There is a short circuit in the secondary power supply;

c) LCD automatic shutdown (LCD power indicator green light or blue light is always on), the problem is:

There is a fault in the high-voltage plate or backlight.

Is the memory wiped?

After the memory is excluded, the possibility of the power supply and motherboard is relatively large!

Motherboard or power supply problems, heat dissipation problems, let's rule it out.

If the host can work, the power supply should be fine, but the main problem is the motherboard.

What is the reason why the computer is turned on and the monitor does not light up? What to do?

If there is too much dust in the machine, and the contact is poor and causes a crash, check the CPU and graphics card heat dissipation, dust removal, oiling, or replace the fan, you can clean the chassis and plug all the connections tightly. 1. If the screen is not displayed after booting, it may be that the cable connecting to the screen is loose, as long as you find the cable connecting to the screen, plug it in! 2. If the cable is plugged in and the screen and keyboard light are still not on, it may be caused by poor memory contact.

You need to unplug the power supply and remove the screws on the left side of the chassis. Remove the left plate. Next to the fan of the motherboard, you can see 2 or more slots.

3. Replace the memory module, and after the change, boot it for testing. If it still doesn't work or you hear a long alarm sound, it means that the memory is not installed, plug it in again or try to plug it into another slot. 4. If the screen still does not light up and cannot be turned on after repeatedly plugging and unplugging the memory, it may be a problem with the graphics card.