Date   : Sat, 01 Apr 2006 15:10:10 +0100
From   : "David Hunt" <dm.hunt@...>
Subject: Re: Now Roms including Was Exile now off topic

> > A useful trick is to use a 28 pin turned pin socket as a carrier.
> Indeedy. Well any socket at a push, but a nice turned pin one is far
> more reliable and a better fit.
> 
> > The whole assembly can then be plugged back in.  If you've broken
the
> legs
> > off at the package edge, you're out of luck!
> Well not completely. With a plastic package (admittedly not common on
> EPROMs) its possible, with extreme care, to file/grind back the
plastic
> around the embedded stump of pin, then put the chip into the socket,
> insert a stiffish bit of wire so that it presses securely against the,
> only very slight exposed, stump, then feed a little flux and solder on
> to ensure good contact. I've done it a couple of times, on 62256s
(when
> you only got two and a handfull of change from £100, and £100 was
worth
> a lot more) which, due to my penchant for flying address and write
wires
> all over the place, have probably suffered more than any other chip at
> my hands, and on a Super-287 FPU, back when one of those was a holy
> grail of performance) and its a fair bit of hassle, but better than
> throwing away a more valued chip.
> 
> 
> > I've often used this trick to get copies of damaged EPROMs, then
burn
> new
> > ones as working replacements.
> Several of my, more frequently moved, ROMs have flat-pin IC sockets as
> permanent fitments. it just makes them easier to plug in, and doesn't
> seem to have any performance hit. Flat pin because I've replaced a lot
> of the sockets on my board with turned pin jobbies, and don't want to
> wear the inserts out plugging turned pin into turned pin, which wears
> fast with removal/insertions, and the chips tend to end up having a
bad
> contact at that point. Flat pin into flat pin doesn't wear so fast, as
> the sockets are springy. The electrical connection is fine, but
> mechanically is not so good.

Repairing broken pins is the reason I bought my first microdrill. I
could
carve away quite a bit around a broken pin on plastic or ceramic
packages,
then a little liquid flux and a small piece of copper wire and a bit of
solder... Most of the time this hassle would create a working IC. I put
an
IC socket in my Beebs/Masters on top of the ones already there (saves
the
soldered in socket) and also a socket onto the ROMs (saves the ROMs), I
never had any problems with broken ROM pins or broken motherboard ROM
sockets. I also put a large piece of silicone rubber underneath the
bottom
right hand side of the Beeb so the board doesn't flex when inserting and
removing ROMs. Later I put a couple of ZIF sockets on a ROM/RAM board I
had.

Dave ;)