[time-nuts] HP 5370A socket problem

Didier didier at cox.net
Wed May 20 01:47:19 UTC 2009


Hi Chuck,

I agree, I could not see anything obvious that would indicate these
particular sockets would cause problems, other than they certainly looked
cheap, even considering the date of manufacture. The contact pressure was
quite considerable, based on how hard it was to pull the chips out, so it
probably was not a bad contact between the socket and the pins. There are a
bunch of chips on sockets, and I never tried to find out if a particular
chip was causing the problem. I replaced all the sockets (except the PAL, I
did not have a socket for him.)

The good news is that the PWB has very thin traces (requiring little heat),
and the holes are fairly wide, so unsoldering the sockets was a piece of
cake, with the right tool. I did each unit in about 30 minutes, all
included. The easiest was to remove the plastic part of the socket BEFORE
unsoldering the contacts. It comes off easily when you pull on it. Then each
contact can be removed individually with minimum stress on the board.

One of my two units had evidence of having been in uncontrolled storage for
at least some time before I got it. The case was very dirty, inside the unit
was dusty but relatively clean. The other was relatively clean inside and
out.

One thing for sure, is that until I replaced the sockets, the units would
only work a few days at a time, and wiggling and reseating the PROMs would
fix the problem each time, until next time.

Didier

> -----Original Message-----
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Chuck Harris
> Sent: Tuesday, May 19, 2009 7:52 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] HP 5370A socket problem
> 
> Hi Didier,
> 
> I just had a look in mine, and it uses plain old TI sockets.  
> They may, or may not be gold (I didn't look that carefully).  
> My unit is S/N 2217A01399, so it sits in the middle of your two units.
> 
> I know that my unit is special (because it is mine, of course 
> ;-), but I just don't think it is all *that* special.  I have 
> seen the same TI sockets used on so many different 
> instruments --I would bet more than half the stuff in my shop 
> has them--  They seem to work more often than not.
> 
> -Chuck Harris




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