It's all good. I have ordered the parts I need. I have ran jumpers already. I'm going to substitute the 'unknown' diode with a 1n4007. Time (and input voltage) will tell. I appreciate your input! Any final thoughts on the diode?

 

Zener diodes are designed to block "Reverse Current" until a certain voltage is achieved. For instance; say you have a 5 volt zener diode. Your power supply quickly rises to its output voltage. Suppose that's 4.5 volts. The zener will block current from flowing backwards. But should your supply develop a fault and the voltage rises to - say - 6 volts, the zener along with a current limiting resistor will then begin to conduct reverse current preventing the downstream circuitry from seeing dangerous over voltage conditions.

We don't KNOW exactly what you're replacing. Using the wrong diode can put your circuitry at risk. I mentioned the common diodes because that is what it LOOKS like you have. But you can't go on "Looks". IF you DO install the 4007 and further damage is done to your board - the risk is yours alone.

Back in post #20 I noticed what looks like burn damage. That suggests something else has gone wrong with the board. You could be putting a good diode into a bad situation and it will fail immediately. Until you've fully diagnosed the problem(s) you should wait to order parts. It's possible that only the diode blew out. It's also possible that downstream electronics may have been weakened. Putting a new strong diode in place of the failed one COULD result in blowing out the rest of the downstream electronics. Make SURE you have found the fault.

Had a fuse blow in an amplifier. Replacing the fuse only resulted in blowing another fuse. The fault in THAT instance was a shorted bridge rectifier. When the fault was uncovered and corrected the amp no longer blew fuses. I could have put a thousand fuses into the amp and none would have survived. Only after FIXING the problem can you replace other parts. What you may have experienced is a cascading failure. That means when one component fails it can cause several more to fail in an instant. That's why you need to fully diagnose the problem before you throw money at it.