Power Supply Output Dropping till 0

[Dexter'sLab]

Hi All,

I have a power supply with multiple outputs. 12v, 5v, -5v. When I power up the unit. I can measure the output voltages but its dropping very fast, from 12v drops to 0, from 5v drops to 0. Anybody knows the possible cause? I already changed the filter caps but still same.. Thanks in advance!

 

[amayilsamy]

Post Your Schematic..

 

[Dexter'sLab]

Post Your Schematic..

I don't have the schematic but I can post the photo and model. maybe you are familiar with this p.supply. Thanks!!

 

[amayilsamy]

Disconnect the load from power supply.

Measure the power supply output voltage. If its no drop, check the load there is any short circuit.

And also measure the load how much current draw..

 

[Dexter'sLab]

Hi amayilsamy, Thanks for your reply. I still not doing the load test. its actually dropping even without load.
When I turn on the p/supply. U can get the output (12v, -5v, 5v) but its dropping fast. till no reading on your multi-tester. Then turn on again, but same situation. get output for a while then dropped.