17 Mar
2013
17 Mar
'13
12:53 p.m.
Powered up an old Compaq Portable II and was greeted with a cloud of
smoke; a tantalum cap's gone to capacitor heaven (it's next to silicon
heaven).Unfortunately it's now so far gone I can't read its value --
anyone have a schematic or know what the capacitor at C19 is supposed to be?
Thanks,
Josh
19 Mar
19 Mar
1:13 p.m.
Actually never mind -- I found the capacitor's sister (and it was 16uF,
25V) and replaced it. Power supply is happy again (though it still smells
like fried capacitor).
Unfortunately (previously unknown to me) this system has a very large
battery in it and you can guess what comes next: it's mounted to the
underside of the motherboard and did a very significant amount of damage to
it and some of the system chassis. I can't foresee it being worth the
extreme effort it'd take to repair.
So, two questions:
1) Anyone have a spare Portable II motherboard?
2) Alternately: Anyone need any Portable II parts? Everything else seems
to be working (hard drive needs a bit of coaxing to get spinning).
- Josh
On Sun, Mar 17, 2013 at 12:53 PM, Josh Dersch <derschjo at gmail.com> wrote:
Powered up an old Compaq Portable II and was greeted
with a cloud of
smoke; a tantalum cap's gone to capacitor heaven (it's next to silicon
heaven). Unfortunately it's now so far gone I can't read its value --
anyone have a schematic or know what the capacitor at C19 is supposed to
be?
Thanks,
Josh
1:53 p.m.
You might try removing the battery and motherboard, and cleaning it with
denatured alcohol or MEK. Won't hurt the motherboard, but it does remove
the corrosion. If the corrosion is severe, check the solder joints for
damage.
If all else fails, I have a selection of Compaq luggables.
Cindy Croxton
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Josh Dersch
Sent: Tuesday, March 19, 2013 3:14 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Compaq Portable II Power Supply schematic (or capacitor ID)
Actually never mind -- I found the capacitor's sister (and it was 16uF,
25V) and replaced it. Power supply is happy again (though it still smells
like fried capacitor).
Unfortunately (previously unknown to me) this system has a very large
battery in it and you can guess what comes next: it's mounted to the
underside of the motherboard and did a very significant amount of damage to
it and some of the system chassis. I can't foresee it being worth the
extreme effort it'd take to repair.
So, two questions:
1) Anyone have a spare Portable II motherboard?
2) Alternately: Anyone need any Portable II parts? Everything else seems to
be working (hard drive needs a bit of coaxing to get spinning).
- Josh
On Sun, Mar 17, 2013 at 12:53 PM, Josh Dersch <derschjo at gmail.com> wrote:
Powered up an old Compaq Portable II and was greeted
with a cloud of
smoke; a tantalum cap's gone to capacitor heaven (it's next to silicon
heaven). Unfortunately it's now so far gone I can't read its value --
anyone have a schematic or know what the capacitor at C19 is supposed
to be?
Thanks,
Josh
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2904 / Virus Database: 2641/6188 - Release Date: 03/19/13
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2904 / Virus Database: 2641/6188 - Release Date: 03/19/13
2:29 p.m.
Yeah, I spent an hour or so cleaning things up with a toothbrush and some
vinegar, soap and gentle abrasives. It's looking like about half the ISA
slots will need work (quite a number of pins on the underside have
effectively been dissolved away) and a number of traces have pretty bad
damage. Not saying it's impossible to fix, just that I doubt I'll ever
find the will to do it :).
- Josh
On Tue, Mar 19, 2013 at 1:53 PM, Cindy Croxton Electronics Plus <
sales at elecplus.com> wrote:
You might try removing the battery and motherboard,
and cleaning it with
denatured alcohol or MEK. Won't hurt the motherboard, but it does remove
the corrosion. If the corrosion is severe, check the solder joints for
damage.
If all else fails, I have a selection of Compaq luggables.
Cindy Croxton
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Josh Dersch
Sent: Tuesday, March 19, 2013 3:14 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Compaq Portable II Power Supply schematic (or capacitor ID)
Actually never mind -- I found the capacitor's sister (and it was 16uF,
25V) and replaced it. Power supply is happy again (though it still smells
like fried capacitor).
Unfortunately (previously unknown to me) this system has a very large
battery in it and you can guess what comes next: it's mounted to the
underside of the motherboard and did a very significant amount of damage to
it and some of the system chassis. I can't foresee it being worth the
extreme effort it'd take to repair.
So, two questions:
1) Anyone have a spare Portable II motherboard?
2) Alternately: Anyone need any Portable II parts? Everything else seems
to
be working (hard drive needs a bit of coaxing to get spinning).
- Josh
On Sun, Mar 17, 2013 at 12:53 PM, Josh Dersch <derschjo at gmail.com> wrote:
Powered up an old Compaq Portable II and was
greeted with a cloud of
smoke; a tantalum cap's gone to capacitor heaven (it's next to silicon
heaven). Unfortunately it's now so far gone I can't read its value --
anyone have a schematic or know what the capacitor at C19 is supposed
to be?
Thanks,
Josh
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2904 / Virus Database: 2641/6188 - Release Date: 03/19/13
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2904 / Virus Database: 2641/6188 - Release Date: 03/19/13
2:43 p.m.
You might try removing the battery and motherboard, and cleaning it with
denatured alcohol or MEK. Won't hurt the motherboard, but it does remove
the corrosion. If the corrosion is severe, check the solder joints for
damage.
THe battery electrolyte is most likely alkaline (potassium hydroxide?) and
a chemically weak acid is quite useful or shifiting it. I use a
solution of citric acid, it smells nicer than vinegar :-)
Of course if the corrosion has damaged tracks on the PCB, you've got a
lot of work ahead of you...
-tony
4248
days inactive
4250
days old
4 comments
3 participants
participants (3)
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ard＠p850ug1.demon.co.uk -
derschjo＠gmail.com -
sales＠elecplus.com