I have a very large high voltage device that a friend asked me to take a look at. It has a bunch of BIG thyristor packages (Semikron, SKKT 106/18 E, Dual Thyristor Module, 600A 1800V).
I'm testing them on a Fluke 87V multi-meter, and they all read EXACTLY the same.
In Diode mode, they all read 0.018v between gate and cathode in both directions, open circuit on all other pins.
In Resistance mode, they all read 18.1 ohms between gate and cathode in both directions, open circuit on all other pins.
I would assume that this means that the devices have all failed in exactly the same way with a gate to cathode short, but it would be very odd if this was the case.
Does anyone think that these devices have failed with a gate to cathode short, or would you expect this behavior on a multi-meter?