troubleshooting a biuld - basic diode question

[plexi12000]

hey tone gods......  using the ol MM....it seems in my power supply, I have a break in, or around the polarity diode.   I have 9v before it, but not after it.

if not a poor solder joint....suppose I overheated it and cooked it.  will a diode still pass current?

Thank you!

[GGBB]

If it fails, it fails unpredictably - either open, short or somewhere in between (resistance). The latter two pass current.

[antonis]

If your polarity protection diode is in series with +9V, then you've probably burned it out..
(but, if diode is a 1N400X type, then you've probably burned out some other following items..)

If it's in parallel with + & -, then you have a short circuit which should have blown up your fuse..
(or your PS in case of an unfused one..)

[GibsonGM]

So, what kind of diode was it?  1N4148, or 1N400X type?    Is it black with a silver band, or glass?

[EBK]

So, what kind of diode was it?  1N4148, or 1N400X type?    Is it black with a silver band, or glass?

Or, is it too charred to tell? 

[GibsonGM]

"Can't find what's wrong with it, sorry. I spent hours last night going over the board, even hooked up some external speakers...nothing.  Are you sure your outlet at home has power??" 

[duck_arse]

So, what kind of diode was it?  1N4148, or 1N400X type?    Is it black with a silver band, or glass?

Or, is it too charred to tell? 

that board's been hit by the Mother Of All Diodes.