Hi,
Fluke 45, was working perfectly until suddenly stopped switching to the resistance function while in use. The resistance measurement doesn't work, mV and 3V DC ranges also, as well as continuity (always on/beeping). Higher voltage ranges are fine, current measurements as well. Pulled out the service manual...
I've traced it to the K1 relay, which seems to be stuck in the set position. Unfortunately, it doesn't appear to be a problem with the relay. I'm currently guessing the U1 chip isn't sending the reset signal when switching ranges or functions. I can capture the set/reset signals for the other relays and the set pulse for K1, but no reset. It's not the driver (U2), there's just nothing on U1's FC0/28 pin at all.
I've found no mention of this failure mode anywhere. I presume U1 will need replacing? Any idea where I can find one?
Thanks,
T.