[volt-nuts] Two 4338B high resistance meters fail on the same range - Keysight can't adjust EEPROM of either.

Dr. David Kirkby drkirkby at kirkbymicrowave.co.uk
Wed May 2 14:33:30 EDT 2018

On 2 May 2018 at 18:27, Charles Steinmetz <csteinmetz at yandex.com> wrote:

> Dave wrote:
> This has certainty got me thinking about what might be happening, although
>> the fact Keysight have said they can't update the EEPROM, suggests they
>> have the software to do it.
> Or does it mean they have lost the software to do it?  Does the cal
> certificate have "as received" and "as adjusted" error readings for other
> ranges?  If not, perhaps they adjusted nothing, which would leave open the
> possibility that they simply cannot adjust these meters anymore due to lack
> of software.
> Best regards,
> Charles

I don't have a cal certificate - only a report of how it was received


and an email saying it can't be updated.


Hi David,

We’ve a High Resistance Meter for calibration, but the instrument is faulty.

Model: 4339B

Serial Number: JP1KD01746

Service Order: 1-9957310275

The calibration has failed, I’ve attached a copy of the calibration

Automated adjustments were attempted. Source Voltage Adjustment could be
completed ok, but the Ammeter Adjustment could not be completed.

I’ve passed the instrument to our repair team who will investigate the
fault, and arrange for a repair quote to be sent out.

The fact the source voltage could be adjusted suggests they could update
the EEPROM, but I'm puzzled why the ammeter adjustment could not be
completed. I'm not sure if they have updated the source voltage at this
point. Every voltage is low, but all are in spec. I'd hope they would be
able to increase the output voltage a little there.

For what it is worth, here's the cal certificate of one I sent in a month
or so ago.


I was told that one needs a new CPU. I might have some more information
tomorrow, as Keysight (UK) are contacting the USA for support.


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