Repair Q: Diode in Ibanez MDL20 (W03C to P6KE)

[tommy.genes]

Bought a broken Ibanez MDL20 Modulation Delay III on eBay. Since the seller said it had been fried by an incorrect power supply, the first thing I did was check the diode across the DC input. It was shorted in both directions, and removing it allowed the rest of the circuit to work. It's a very cool pedal too - I'm already planning to do high cut and external feedback mods to it...

Still, I want to replace the diode to have that protection. A similar schematic (Ibanez DFL) shows the part number "W03C". Mouser cross-references that to 112 different Transient Voltage Suppressor (TVS) diodes in the P6KE family. Any suggestions on which one to use, or on any more common substitues? What are the pertinent specification values I should be looking for?

BTW, markings on the diode and PC board indicate it was a directional device. I see that TVS come in both directional and bi-directional versions.

Thanks,
-- T. G. --

[tommy.genes]

A small bump, even though I think I'm beginning to understand this better.

Would the 1N4739A (9V) or 1N4742A (12V) Zener diodes from Small Bear be suitable for this?

Also, has anybody here used series fuses inside their pedals, like is shown HERE?

This could prevent the diode from failing as an open circuit, thereby letting the offending reverse voltage into the sensitive innards of your pedal anyway. And using surface-mount fuses would not require much space, but would be harder to repair than clip-mounted (but larger) 5mm cylindrical fuses.

-- T. G --