It doesn't look bad TBHSuppose so if you’ve a burnt diode?
Tried and had the Same resultif its gone open circuit it wouldn't have any continuity, but you should be testing it on a diode setting, not continuity.
.....and someone who knows what they are talking about will be here soon
Diodes fail open not closed.
Absolutely. Most diode failures I've seen go full short circuit, leading to potentially catastrophic failure in other components.If you're lucky...
Dave H. (the other one)
Ideally, you should use a diode-specific range as diodes need a 0.6v feed to conduct. Many multimeters won't induce that level of voltage on the resistance range.Yes they can.
Remove each diode from the circuit.
Set your meter to Ohms.
Test both ways, one will give a few ohms, thet way other Mohms.
The 4 should all be about the same value, if not they are shot.
It should be easy enough to test, even on the board.
As per gaz's diagram identify the AC input pins and then check with a multimeter on diode setting that you have current flowing in one direction to one of the other pins, and nothing in the opposite direction. If you get a short in either (although a short would very very likely show in both directions), or open in both, then it's stuffed.
They are not expensive, and you can also replace the unit with four discrete diodes if that's all you have lying around, so it's worth just replacing it.
Per Dave's point, if you're lucky and it's failed open circuit then it's likely that the rest of the board escaped damage!
I hope that , Also because from a first quick check IGBTs are fine , capacitors don't charge , and there is not power on the entire boardIt should be easy enough to test, even on the board.
As per gaz's diagram identify the AC input pins and then check with a multimeter on diode setting that you have current flowing in one direction to one of the other pins, and nothing in the opposite direction. If you get a short in either (although a short would very very likely show in both directions), or open in both, then it's stuffed.
They are not expensive, and you can also replace the unit with four discrete diodes if that's all you have lying around, so it's worth just replacing it.
Per Dave's point, if you're lucky and it's failed open circuit then it's likely that the rest of the board escaped damage!
I hope that , Also because from a first quick check IGBTs are fine , capacitors don't charge , and there is not power on the entire board