On Mar 12, 4:31 pm, wrote:
I have just fixed an power supply by replacing a bulging capacitor.

The capacitor is connected to diode. And the diode becomes hot and
makes a black spot on the board since the faulty cap.

I check the diode with a multimeter and it tests great.

The repaired power supply( cap replaced) has been tested for several
hours and no problem yet.

Question: Is there any way to check whether the diode is working
100% ?

Thanks!

It seems like the repair worked, but the hot diode concerns me. Your
description is a little hard to understand. Did the diode get hot
before or after the capacitor was replaced?

In any case, the black mark by the diode isn't a good sign. Whether
the mark was cause by the diode overheating or leakage from the
bulging capacitor, I would replace it. As another poster tersely
pointed out, diodes are inexpensive.

For a definitive measurement, don't test the diode in place. Rather,
unsolder one of its leads from the circuit board and then test it with
your voltmeter's continuity checker.

-Dave