The problem of poor load capacity of AC switching power supply
1. Reasons for the poor ability of AC power supply
The AC power supply can work normally when it only supplies power to the motherboard and the floppy drive. When the hard disk and optical drive are connected, the screen turns white and cannot work normally.
The possible reasons are as follows: the operating point of the transistor is not selected properly, the high-voltage filter capacitor is leaking or damaged, the Zener diode is heated and leaked, and the rectifier diode is damaged.
The above analyzes the phenomenon and common causes of poor AC power debt capacity.
2. The solution to the poor ability of AC power supply
Swap each transistor in the oscillation circuit to increase its gain, or increase the operating point of the transistor. After detecting the faulty parts with a multimeter, replace the thyristor, Zener diode, high-voltage filter capacitor or rectifier diode.
Half of the debt capacity of the AC power supply can be solved by the above methods. If it still cannot be solved, then it is necessary to contact professional and technical personnel, and they will deal with the fault.
