[marios_mar]

what does a diode that is getting real hot mean?

 

[00940]

it could mean that it is undersized and is receiving to much current.

Could you be more specific ?

 

[marios_mar]

I have a PSU that should give positive and negative at both ends. I only get the positive part. And a diode on the "positive" part of the PSU gets real hot.

 

[Excalibur]

Like "00940" said, there is too much current flowing through the diode or the diode's current rating is not adequate for the circuit it is being uesd in. Also, there may be a short. Trace back through the circuit associated with the cathode side of the diode for a short. When you find that, it may be the cause of the missing (-) voltage also. If not, you have two problems.