There is a good trouble-shooting tree in the 10811 manual that addresses these issues.
I had a 10811 where the oven would not come on. I found the thermal fuse open and even ordered the replacement part from HP. It was only a couple bucks IIRC. I also found some close ones for only a few pennies. Once replaced, I went through the trouble-shooting tree only to discover all things working correctly. It has done fine since with no further fuse failures. Joe -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of Dan Rae Sent: Tuesday, September 14, 2010 10:28 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Questions about HP 5370B On 9/14/2010 1:23 AM, John Miles wrote: > >> As Bruce suggests, you'll want to peek inside to see that you >> really do have >> a 10811 oscillator. If so, then it sounds like the thermal fuse >> (F1, inside >> the 10811) might be open. > Just short it out, or if you like, put in an NTE part with a similar temp > rating. It serves little or no useful purpose. > > -- john, KE5FX > > > I hate to disagree with John who knows a heck of lot more than I ever will, but in this case it will protect the oven from cooking up if the control circuit fails with the heater full on, which can happen. I did have a 5370B with a 10811 that had a bad thermistor in it as well as an open fuse. I'd guess that's why -hp- fitted it. But yes, the thermal fuses can and do fail open for no good reason, and it sounds like this has happened here, but I would not recommend shorting it out permanently. Dan _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
