28 Oct
2017
28 Oct
'17
11:40 a.m.
-----Original Message-----
From: Maciej W. Rozycki [mailto:macro at linux-mips.org]
Sent: 28 October 2017 18:48
To: rob at jarratt.me.uk
Cc: 'General Discussion: On-Topic and Off-Topic Posts'
<cctalk at classiccmp.org>; 'dwight' <dkelvey at hotmail.com>
Subject: RE: Cleaning and Restoring a Badly Corroded PSU
On Sat, 28 Oct 2017, Maciej W. Rozycki wrote:
On second thoughts if solder has corroded, which may well be the case
given
Did you
manage to remove this part without destroying it and without
damaging the board?
Yes, in all cases. I didn't recall any issues with unsoldering this
part really, using a simple 40W iron and desoldering wick only, and
extra flux from a pen. the overall state of your PSU, then you will have
troubles melting it,
because,
obviously, oxides and other compounds which would have
formed won't
usually
melt as easily as metal. In that case I suggest
trying mechanical means
to
remove the contamination and then applying extra
solder to increase its
mass
in the joint before trying to undo it.
Yes, I did the extra solder thing too, the problem there was getting it to
flow properly, even with extra flux from a pen. I couldn't get much new
solder into the joint. I never thought to remove the contamination though,
which is probably part of the reason why the extra solder would not flow,
one to remember next time.
I do remember having problems with handling corroded
joints next to
leaked
capacitors in my H7874 PSUs, even though those
specific joints didn't have
any
way to lose heat easily.
HTH,
Maciej