HP 3478A / Calibration failure

[Eltax1693]

I bought my HP 3478A from Ebay a month ago. It passes the self test, so I sent it to a cal lab. [replaced the battery too]
Everything went fine, except the ACV and ACA ranges. "not possible to adjust".

What can be wrong?

TNX

[singapol]

I bought my HP 3478A from Ebay a month ago. It passes the self test, so I sent it to a cal lab. [replaced the battery too]
Everything went fine, except the ACV and ACA ranges. "not possible to adjust".

What can be wrong?

TNX

The self test only test display , memory and A/D convertor communication only. Read chapter 3-60 page 3-7
of the service manual on self test.. Why Ac volt and current cannot calibrate? Unfortunately  I think AC measurement circuit has  been damage by previous owner overloading input. Read Service group B - AC volts and Ac current troubleshooting on page 7b-1 of sevice manual. Hope you can find a good technician to repair HP3478A.

HP 3478A service manual-
http://www.arimi.it/wp-content/Strumenti/HP/Multimetri/hp-3478a-Service.pdf

[dom0]

iirc the self test does show whether valid calibration data was loaded from the cal SRAM.

[Eltax1693]

OK, tnx for your help.