First time 2001 user here. Bought one on ebay for a good price.
Received the unit, self test ok. Opened it up to check the production date, closed it and made some measurements.
Then I had approx 7V on ACV measurements with nothing connected. With AC coupling the 7V stayed even with shorting plug inserted. With AC+DC coupling it read 0V. Self test gave one error (forgot which one). Opened it up again and found relay K503 stuck closed. Took it out and AC measurements are ok, but self test throws 407.1 Front end, 407.2 Front end, 407.3 Front end, 410.1 TRMS, 411.1 TRMS, 411.2 TRMS as TheSteve had before.
I don't have the original relay available, so I used another reed relay. Error messages are gone except 408.6 /100 Freq Comp. But this error is not always there. I hope it will be gone when I receive the original relay.