Hello, Seems this is the month for errant 3458A DMMs. I have a unit that was working fine and passing both the power on and full Self Tests. The unit has been stored away for a few years and is very clean. After several days of continuous error free operation, is started kicking out the error: 114 System Error – multislope rundown error At first, the error was only every few minutes (all default power on settings) but is now almost constant. I can clear the error and proceed for a few more seconds. It is also the only error in the stack. Suspicious of electrolytics, I checked all voltages and ripple on both outguard and inguard supplies with everything looking good. I did replaced some caps that showed barely low values. This unit is 11 years old. At this point, I am reasonably sure it is not power supply related. I am also sure it is not a cal related condition as I started a procedure and it would not get past the first offset section – same error. Does anyone have any documentation of knowledge of this error? ERRSTR 114 is not mentioned in the Assembly Level Repair manual. Thanks. DonRegards... Don
________________________________ From: Dick Moore <[email protected]> To: [email protected] Sent: Sunday, August 2, 2009 2:08:08 PM Subject: Re: [time-nuts] new request for 3458A info On Aug 2, 2009, at 5:00 AM, [email protected] wrote: > > Message: 4 > Date: Sun, 02 Aug 2009 03:00:06 +0200 > From: "Dr. Frank Stellmach" <[email protected]> > Subject: [time-nuts] 3458A info > To: [email protected] > Message-ID: <[email protected]> > Content-Type: text/plain; charset=ISO-8859-15; format=flowed > > Dick, > > did you already try an ACAL DCV, or ACAL ALL from the front panel? > > Maybe the false cal constants will be set correctly. > > In the calibration manual, its explained, which constants are set by > atocal (and cured), and which one are set by basic calibration, > requiring external standards (10 volt, 10kohm). > I think, DAC Vos and 10V gain are set by ACAL. > > Frank Yes, tried all that. Last night I gave up and opened the box, which I had been reluctant to do -- DC board had burned components right in the center. There are 2 unrecognizable ICs and a handful of resistors, etc, and a badly charred board. Probably unrepairable. Have no idea what could have happened to make it so bad without also killing the power supplies, which are AOK. Shouldn't have been anything on the input, which is protected against over-voltage/-current. Too bad. Thanks for all the advice and tips. Dick Moore _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
