writes:

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.

If it tests good in-place, it won't test bad when removed.

However, the inverse (??) may be true.

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