[time-nuts] Getting a 5370A tomorrow - How do i test it works

John Miles john at miles.io
Thu Aug 29 18:01:33 EDT 2013


> I goofed in one of the steps - Step 6 , where i should have selected DC
> on both AC/DC switches , they were unfortunately on AC.
> 
> When i power the unit off/on it starts up fine (the start/stop) leds are
> blinking , but the display shows 0.00 , and once in a while if i'm lucky
> it arms and show 99.7 or so .... If i leave it .... It ends in Err02
> after a while.
> 
> Any hints ?

There is probably nothing too seriously awry.  Physical intermittents can be
a hassle with 5370As.  Reseat all of the ROM chips along with everything
else that's in a DIP socket, and see if that helps.  

You also may have an intermittent contact in one of the front-panel
switches.  They are not very well designed and can easily bind up.  HP
should have used high performance RF relays for all of those switches (and
they could have afforded to do so, since the boards were used in their most
expensive counters, the 5345A and 5370A/B).  You may need to pull the front
panel board and verify that all of the switches move freely with good
contact action.  Swab some Caig ProGold or a similar product on the contacts
and pads while you're in there.

If you end up needing to service the board, a 5345A can act as a parts
donor.  Unlike 5370s, 5345s are practically free for the shipping these
days.  I'm not sure their front end boards are configured identically, but
the ones in my 5370Bs are marked 05345-60138 so they can't be too different.

-- john, KE5FX
Miles Design LLC




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