[time-nuts] HP 5370A socket problem

[Ulrich Bangert]

> For a cheap (slightly)longer term fix, wipe the IC pins 
> with a swab moistened with WD40! 

BALLISTOL is also recommended for that job.

Best regards
Ulrich Bangert

> -----Ursprüngliche Nachricht-----
> Von: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Robert Atkinson
> Gesendet: Mittwoch, 20. Mai 2009 08:58
> An: Discussion of precise time and frequency measurement
> Betreff: Re: [time-nuts] HP 5370A socket problem
> 
> 
> 
> Hi,
> I've not seen socket problems on my 5370B, but have with 
> other equipment. The TI leaf contact sockets seem to be the 
> worst. I've often wondered if it's a plating compatability 
> issue. Small differences in plating composition might be 
> causing problems. Retention force is not an issue as noted, 
> but high retention could be caused by corrosion. Often just 
> shifting the IC's in their sockets will effect a short term 
> cure. For a cheap (slightly)longer term fix, wipe the IC pins 
> with a swab moistened with WD40! 
> 
> Robert G8RPI.
> 
> --- On Wed, 20/5/09, Chuck Harris <cfharris at erols.com> wrote:
> 
> > From: Chuck Harris <cfharris at erols.com>
> > Subject: Re: [time-nuts] HP 5370A socket problem
> > To: "Discussion of precise time and frequency measurement" 
> > <time-nuts at febo.com>
> > Date: Wednesday, 20 May, 2009, 5:06 AM
> > Hi Didier,
> > 
> > I have never doubted for one moment that the sockets were causing
> > your problems, I just wonder how prevalent the failure is
> > in the
> > universe of 5370's.  I have HP equipment that is both
> > newer and
> > older than my 5370A, that has the same sockets.  It
> > would not
> > surprise me at all to find the 5370B has the same exact
> > sockets
> > too.
> > 
> > Double sided boards are a treat to work on with
> > desoldering
> > equipment.  Multilayer boards suck up so much heat
> > that they
> > are a real problem.  It helps to cook them on an IR
> > preheater for
> > a while before removing parts.
> > 
> > -Chuck Harris
> > 
> > Didier wrote:
> > > 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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> > 
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> 
> 
>       
> 
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