already desoldered your bios batteries?

Post new topic   Reply to topic    CPU-World.com forums Forum Index -> Vintage Computers and Boards
View previous topic :: View next topic  
Author Message
Unzlbunzl



Joined: 30 Jan 2007
Posts: 468
Location: Graz, Austria

PostPosted: Mon Feb 11, 2008 8:37 pm    Post subject: already desoldered your bios batteries? Reply with quote

when browsing through my (what i call) essential hardware today, i re-discovered my nice full-size AT 386DX mobo (16 memory slots, yeah), besides lots of unidentified memory modules i'll probably post later. battery acid has begun to eat some copper leads on it - will be an awful job to repair this. are those computer collectors out there beware of this threat?
Back to top
View user's profile Send private message [ Hidden ]
CPUShack



Joined: 16 Jun 2003
Posts: 34259
Location: State of Jefferson, USA

PostPosted: Mon Feb 11, 2008 11:58 pm    Post subject: Reply with quote

this is/was a pretty common problem, and why they made lots of replacements for those soldered on batteries.

You know the ones that had velcro on them for easy attachment to the inside of the case.

_________________
New for 2025! The CPU Shack has a co-processor!

Visit The CPU Shack of microprocessor history and information.
Back to top
View user's profile Send private message   Visit poster's website AIM Address MSN Messenger
Unzlbunzl



Joined: 30 Jan 2007
Posts: 468
Location: Graz, Austria

PostPosted: Tue Feb 12, 2008 12:10 am    Post subject: Reply with quote

from what ive seen so far this external batteries where have more of ODP than ODPR

Last edited by Unzlbunzl on Tue Feb 12, 2008 4:48 am; edited 1 time in total
Back to top
View user's profile Send private message [ Hidden ]
JAC



Joined: 24 Jul 2005
Posts: 3469

PostPosted: Tue Feb 12, 2008 4:15 am    Post subject: Reply with quote

nasty!
Back to top
View user's profile Send private message  
el_gecko



Joined: 25 May 2005
Posts: 1553
Location: Nice, France

PostPosted: Tue Feb 12, 2008 4:52 am    Post subject: Reply with quote

Does somebody have a tip to avoid that? Could we unsolder these batteries and keep these mainboards still functionnal?
_________________
My microprocessor collection: The Gecko's CPU Library
Back to top
View user's profile Send private message [ Hidden ] Visit poster's website
Chiefish



Joined: 23 Sep 2007
Posts: 2153
Location: Northwest N.J. U.S.A

PostPosted: Tue Feb 12, 2008 6:52 am    Post subject: Reply with quote

No , but i might reccommend a Rear Defroster Repair kit to rejoin those traces on the board, they also have conductive pens that can repair that break in the traces. You can usually find them at an auto parts place.
_________________
"The only reason for time is so that everything doesn't happen at once." A.E.
Back to top
View user's profile Send private message [ Hidden ]
i440bx



Joined: 30 May 2004
Posts: 1349
Location: Germany

PostPosted: Tue Feb 12, 2008 8:24 am    Post subject: Reply with quote

I had the same Problem with my 286er Board.

I saw that the acid began to eat the Board and replaced the Battery with an High-Power Capacitor like this:
.

It has around 20Farad and thats enough vor some months witout Power.

They are called "Gold Caps" Cool

_________________
i440BX
My collection: http://www.x86-guide.net/i440bx/en/collection.html
Back to top
View user's profile Send private message [ Hidden ]
doccybrown



Joined: 03 Oct 2005
Posts: 1736
Location: Germany

PostPosted: Tue Feb 12, 2008 10:07 am    Post subject: Reply with quote

I`m replacing this nasty NiCd-accumulators
with 3V lithium-batterys. Older mainboards
are charging the NiCd-accumulators so using
a diode is judicious. The diode (preferable a germanium-diode
which have a low forward bias of 0.2-0.3V) will only pass the
current one way - from batt to mobo (assumed the
diode is placed correctly) Wink
Without diode you may risc the lithium-batt blows up Shocked
This works also with mobos that are using 4,5V packs!
And I have seen lithium-batterys that had ~3,0V after 8 years
of buffering, and not one leaking! Very Happy
/Doccy

_________________
Ordem e Progresso
Back to top
View user's profile Send private message  
Display posts from previous:   
Post new topic   Reply to topic    CPU-World.com forums Forum Index -> Vintage Computers and Boards All times are GMT - 5 Hours
Page 1 of 1
Jump to:  
You can post new topics in this forum
You can reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum

Powered by phpBB © 2001 phpBB Group