22 Aug
2002
22 Aug
'02
5:04 a.m.
How many of you remember the problem of chips coming unseated in older
computers (like the PET) and having to push all the chips down as the
equipment ages?
I've now got this problem with my Kurzweil MIDIBOARD (a 6502-based MIDI
keyboard controller). A few months ago I had to open it and reseat all
the chips. Now I have to do it again.
Does anyone know any tricks to keep this problem from occuring? I fear
I'm going to have to do this a lot now, especially with the vibrations
of playing the keys.
Thanks for any tips.
- Bob
22 Aug
22 Aug
5:17 a.m.
On Thu, 22 Aug 2002, Bob Lafleur wrote:
How many of you remember the problem of chips coming
unseated in older
computers (like the PET) and having to push all the chips down as the
equipment ages?
also Apple ][
Does anyone know any tricks to keep this problem from
occuring? I fear
I'm going to have to do this a lot now, especially with the vibrations
of playing the keys.
Best solution? unsolder all of the crummy sockets, and replace them with
Augat gold plated michined sockets. Kinda a lot of work.
5:40 a.m.
--- "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com> wrote:
Best solution? unsolder all of the crummy sockets,
and replace them with
Augat gold plated michined sockets. Kinda a lot of work.
Speaking of which, does anyone know of any surplus sources of said
sockets? I have enough 20-pin and 24-pin turned-pin sockets to
do the projects I need to do (like my GG2 Bus+), but I'm perpetually
short of 14 and 16-pin sockets (as well as 28-pin and 40-pin).
I picked up a handful (all they had) of some 16-pin sockets at
Dayton this year at a price of several-for-a-dollar. If I could
find 14 and 16-pin sockets at $0.10 each in quantity, I'd buy
hundreds.
Oh... just realizing the possibility for confusion - I need solder-tail
sockets, not wire-wrap sockets. I _have_ a lifetime supply of turned-
pin DIP WW sockets of all sizes (up to 64-pin). I would expect WW
sockets to cost more than soldertail.
So... at the moment, the price to beat is 3/$1.35 (B.G.Micro). I'm
sure I can do better at Dayton next year, but that's 9 months away.
I could really use a few dozen right now to finish upgrading the RAM
in my stack of DEC Professionals (the daughter cards have 16 DRAMs
each - two per Pro350, 1 per Pro380 - remove old 4164s, add 41256s
and install two jumpers). I have enough sockets for one daughter
daughter card.
-ethan
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5:25 a.m.
Rumor has it that Bob Lafleur may have mentioned these words:
How many of you remember the problem of chips coming
unseated in older
computers (like the PET) and having to push all the chips down as the
equipment ages?
Yes, a friend of mine likes to remind me that the standard repair tactic
for the Atari ST line was pick up the machine about 6 inches from the
counter & drop it...
I've now got this problem with my Kurzweil
MIDIBOARD (a 6502-based MIDI
keyboard controller). A few months ago I had to open it and reseat all the
chips. Now I have to do it again.
Does anyone know any tricks to keep this problem from occuring? I fear I'm
going to have to do this a lot now, especially with the vibrations of
playing the keys.
Solder??? ;-)
Seriously, 1 thing you can do that may improve (but not totally fix) the
problem *fairly easily*, is remove the chip[s] from their socket, noting
their orientation, and gently clean the legs of the chips with a white
eraser, then replace. That might extend the amount of time between chip
resocketting...
The only way I know to totally fix the problem without soldering the chips
directly to the board, is to remove the chips, desolder the cheap
single/dual wipe sockets, and install the more expensive ( & reliable)
machine-turned pin sockets, then reinstall the chips. That should eliminate
the problem entirely, or maybe a reseat every coupla decades...
HTH,
Roger "Merch" Merchberger
--
Roger "Merch" Merchberger -- sysadmin, Iceberg Computers
zmerch(a)30below.com
What do you do when Life gives you lemons,
and you don't *like* lemonade?????????????
7:03 a.m.
This problem is common with lower-quality IC sockets.
Sockets that do not use the fancy machined-pin contacts have a upwards
spring-force against each pin.
Add thermal cycles, and the chips will start creeping out of the socket.
Part of the problem is mechanical creep, but oxidation is also a factor,
as the sockets that exhibit this
problem are tin-plae phosphor-bronze. Gold-clad sockets don't generally
fail this way, and the round
pin (Augat style) socket pins basically never fail.
Bob Lafleur wrote:
How many of you remember the problem of chips coming
unseated in older
computers (like the PET) and having to push all the chips down as the
equipment ages?
I've now got this problem with my Kurzweil MIDIBOARD (a 6502-based MIDI
keyboard controller). A few months ago I had to open it and reseat all
the chips. Now I have to do it again.
Does anyone know any tricks to keep this problem from occuring? I fear
I'm going to have to do this a lot now, especially with the vibrations
of playing the keys.
Thanks for any tips.
- Bob
8:50 a.m.
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5 comments
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participants (6)
-
ard＠p850ug1.demon.co.uk -
bob_lafleur＠technologist.com -
bshannon＠tiac.net -
cisin＠xenosoft.com -
erd_6502＠yahoo.com -
zmerch＠30below.com