[volt-nuts] What's the probability of a random used 3458A passing a Keysight calibration?

[Dr. Frank]

I also saw this, so at least, they will have adjusted this range.

Yes you're right, the ADC is the A3 board. I confused that with the A5 
controller board, which is the only one which had been redesigned to SMT 
components.

There's no chance to identify a refurbished or replaced board, other 
than opening the case and looking inside.
And even then, it's not evident, that the ADC IC is ok. You only might 
do the test according to AN-18.

Replacement boards will have the same part number, which changes only by 
redesign.

Frank