Repairing A4000 leaky NiCd damage?

[Dave G4UGM]

> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Peter
> Corlett
> Sent: 02 January 2015 09:40
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: Repairing A4000 leaky NiCd damage?
> 
> On Fri, Jan 02, 2015 at 04:06:48AM -0500, Charles wrote:
> [...]
> > make sure to change the caps on the cpu card as well.
> > I re-cap many of these for people.
> 
> Is this a specific known problem with the A3640 board, or just a
prophylactic
> fix-all for all machines of that age?  It would perhaps explain the
behaviour
> I'm seeing.

Electrolytic and Tantalum Capacitors seem to be problematic on machines of a
wide range of ages. Sometimes it is obvious they have failed as the caps
have domed tops.
Some times its not so obvious  I would recommend a low-voltage ESR meter
that uses less than 0.6v so it doesn't turn on any diodes.

Dave
G4UGM