DC Power Supply Repair
A friend of mine who deals with industrial machine sent me two 24 Volts DC power supply for repair. As usual i will test the output first and found one of them have a slighlty higher output. Since the DC power supply can work, i began to check on the electrolytic capacitors first with the help from my ESR meter. Before that i discharged all the voltages in the big capacitors. Scanning all the e-caps i found one of the e-caps have a high ESR value (100 uf 25 Volts). After the replacement i found that the output voltage has dropped to normal and running with a load proved the regulation of the DC power supply to be working fine.
The other unit have the same problem and i direct replaced the e-cap and the 24DC volts fan have to be replaced. If these DC power supplies have a major breakdown it would take more time for me to repair.