unknown diode part number

[ksb]

Please help me to identify the correct part number or replacement for diode marked as motorola K02 06 86 302

[Zero999]

It looks suspiciously like a zener diode, going by the case and how it's connected in the circuit, with the anode to what looks like a ground plane and the cathode to a resistor.

I take it you're trying to repair something? What does the circuit do? How do you know the diode is faulty? There's no physical sign of damage such as charring. Do you have a schematic? It's possible it's a different component which is bad.

[MagicSmoker]

It's definitely a zener diode, but it looks like it is part of a crowbar type overvoltage protection circuit in a power supply. Does the anode (eventually) connect to the gate (shorter flag terminal) of the stud-mounted thyristor? If so, the zener voltage will likely be a little higher than the output voltage of the supply.

[Zero999]

Looking more closely, it's not connected to the ground plane, but another pad. I think MagicSmoker is right. It's going to an SCR and is a overvoltage protection crowbar.

[ksb]

Its a Spectrum Analyzer power supply. The diode has no reading at all. Seems like open circuit.

[ksb]

How to find the actual part number?

[MagicSmoker]

The power supply should work without the crowbar. If it isn't then it might be because the crowbar fired and then failed short. So, try removing the thyristor if there is no output but it still draws a heavy current from the mains.

P.S. - this belongs in Repair; maybe move it there or ask a mod to.

[741]

That looks like a Motorola "M". It might be worth establishing the case code, maybe DO204.