IanM wrote in message
...
N_Cook wrote:

Maybe I'll be lucky. Removed 5 ICs and the nicad from that area. Washed
locally with meths and while still wet dremmel and rotary wire brushed
over
that area . Now I cannot find any conduction to/between any isolated
pads or
the plastic/glass less than the 30Meg of my DVM. Made good the IC holes
ready to receive 5 turned pin sockets

ps
I also have a 30K filter on my (valid) email inbox. It is me who
decides
who clogs up my inbox /HD



Sounds like it was just surface contamination or leaky resist. I would
wet scrub it with deionised water with some IPA as a wetting agent using
a abrasive pencil type glassfibre brush to be certain the dremel wire
brush hasn't left any metal contamination that may give you trouble with
metal salts later, Rinse well with dry alcohol and dry thoroughly
with forced air circulation at an elevated temperature. Finally coat
the damaged area with a good brand of solder-through PCB lacquer before
refitting any components.

If I think there is any chance of future battery leakage I usually fit
the new battery through a piece of polyethylene, silicone or ptfe sheet
between it and the board to limit the damage next time.

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL:



Well I suppose that is progress. Back to exactly the same malfunction as
before , but with the 5 original ICs in sockets now. Varying activity on the
analogue side of the ADC and no variation at any of the 8 output digital
lines . Will try a SM ZN449 , which strangely is wider package than standard
DIL. so looks like it will have to be a skewed adaption to fit .
Using the original nicad at the moment, slung underneath. I like the idea of
a silicone bund. I think , if I get this working, I will replace with a
new one , stout-wired upside down, right side of the board , over a
silicone sweet or cupcake mould