[volt-nuts] 3458A Questions - The Sequel

J. L. Trantham jltran at att.net
Sat Oct 29 15:57:27 UTC 2011

I think you are reading a date code on the chip.  In order to read the
firmware, use the front panel controls.

The key sequence is 'Menu' (shift, E), 'R' (shift, Trig), scroll down (down
arrow) to 'REV?' then hit 'Enter'.  Mine returns 8,2.

I looked at the picture of the boards on the Agilent website and the Option
001 version of the A5 board shows 6 EPROM's that appear to be in sockets
with 4 chips installed in U123 - U126, also appearing to be in sockets.  The
non Option 001 A5 board shows the single EPROM, soldered in, but with empty
sockets at U123 - U126.  

Therefore, another question arises.  If I converted my EPROM, U110, and the
three Dallas chips, U121, U122, and U132, to socketed chips, and then sent
the board to Agilent for the 'repair', would Agilent replace the board
because they found it 'non original' or needed to upgrade the firmware or
upgrade the Dallas chips to more modern chips, etc., or would they instead
just replace the chips, leaving the sockets on the board?  Anyone have any
experience sending a meter with a 'modified' board back to Agilent for


-----Original Message-----
From: volt-nuts-bounces at febo.com [mailto:volt-nuts-bounces at febo.com] On
Behalf Of Electronics and Books
Sent: Saturday, October 29, 2011 5:53 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] 3458A Questions - The Sequel

Best is to solder out the Dallas RAMs and the EPROM. You can then put
sockets in. The Dallas RAMs are readable as an eprom and on an eprom
programmer also writable. Desoldering and soldering new sockets took me an
hour. My firmware is marked 9017. Does anyone has a newer version on file.


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