HP Multimeter 3457A ERROR 9

[member_xyz]

Just received HP 3457A Bench Multimeter that keeps coming up with Error 9 "Not Calibrated" with beeping.

Unit passes initial self test with no hardware errors.

Error can be cleared briefly but reappears with change of input function and even change in input readings.

Auto calibration doesn't  change anything.

Input measurements DCV, ACV and current are about 4-5% lower than should be. Haven't checked resistance measurement yet.

Initial internal inspection does not reveal anything wrong at first glance.

Power supply voltages +5V for Logic and Analog section appear OK so do +15V and -15V appear OK.

Reference voltages +10V and -10V are about 150mV out and -1.25V is about 15mv out, not sure if they should be more accurate.

Before I start looking into it in much more detail I would appreciate if anyone familiar with this multimeter can offer any advice.

Cheers.

[member_xyz]

For testing purposes have roughly re-calibrated zero and gain for mid DCV ranges and it appears to be measuring OK and stable. Reference zener LM399H is spot on 7V and appears stable.

At this stage it looks like all it needs is detailed calibration. Can't find any reference in service manual for error "9 NOT CALIBRATED", not sure if 9 is some item  number as there is no mention of ERROR 9 anywhere, and there is only one item in the ERROR log?

Intention is to use this meter in automated setup for low DCV, DCma and resistance where accuracy is not critical, 0.5% will be OK, so hopefully I can calibrate it against my very accurate HP 34401a.

I would still appreciate comments from people that are more familiar and experienced with 3457A.

Cheers.

[poodyp]

Have you checked the EEPROM battery backup? If it's dead and the EEPROM is dead the meter will probably complain until a full calibration is done.

[member_xyz]

Battery is OK at 3.3V

Meter is now behaving OK on re-calibrated DCV ranges.

But it definitely needs full calibration.

Any alternative ideas about calibrating difficult FULL ranges like 300v DC, don't have access to accurate 300v DC source?