Amiga 500+ leaking battery and other issues/questions

[Brian Hoskins]

Nowhere near the worst battery leakage I've seen on an A500+, but even so it's pretty nasty and you're going to want to make sure the the PCB has been fully cleaned.  Please consider the following:

• Post new photos showing the cleaned PCB so we can advise further
• Make sure the pins on the expansion connector have been cleaned.  A fibre pen is your friend here.
• Gary was infected.  Get him out of the socket, make sure the pins are fully cleaned, and - crucially - make sure the socket is not contaminated.  If the socket is contaminated it can sometimes be better to replace than repair.
• There are some PCB traces that go off to Gary in this area.  I can't tell from the photo if any are broken but there are some which look suspect.  You may need to buzz these out.

[Brian Hoskins]

• There are some PCB traces that go off to Gary in this area.  I can't tell from the photo if any are broken but there are some which look suspect.  You may need to buzz these out.

https://www.amigapcb.org/ is your friend here.

[Brian Hoskins]

OK, good job so far but the PCB and components require more work.

The area around U12 requires further cleaning.  I would definitely replace C12.  I would consider replacing U12 also but you have to be careful because the battery leakage has probably compromised the PCB pads and if so it will be easier to damage them.  If you do decide to replace U12 I would recommend carefully cutting it out and then desolder the remaining pins separately - this will allow you to reduce the stress on the individual joints.

Some of the PCB tracks look compromised and you need to buzz them out to check.  In fact I would do this first because if you do have broken tracks, and this is beyond your ability to repair, it might not be worth you doing anything else.

Gary requires attention.  You need to get that IC out of there and thoroughly clean.  Also inspect/replace the socket.
I like that you are considering a proper tool for this.  Careful use of a flat-blade screwdriver will do but it's very easy to cause damage this way.  The tool you suggest looks alright to me.  Even so you will want to be careful - that IC probably won't come out super-easily and if you yank it you'll end up bending pins.  Just go slowly, carefully, with patience and it'll be fine.

[Brian Hoskins]

If I were in your position I would definitely replace that socket rather than try to refurbish it.  That said, it's easy for me to say when I have invested in all the right tools for doing this sort of work.

Desoldering a DIP socket properly can be a bit tricky.  But given that the part is scrap anyway, there's no need to desolder it  "properly".  Here is an improper method that will work and will be easier for you:

Carefully cut away all the plastics to free each pin from its neighbour.  Now, to desolder, you can simply apply sufficient heat to each joint in turn and carefully pull the pin out.  Now, there are two important things here:

• CAREFULLY cut the plastic.  Don't wrench and bend it.  Use good, sharp tools.  Don't damage the PCB!
• When removing a pin, apply sufficient heat and fresh solder.  If the pin still won't come easily, find out why rather than force.

This will be relatively simple for you to do with only basic tools required.  Of course, the DIP socket will be completely destroyed but we are not trying to salvage it anyway.

If you still feel like you can't do it then you can try the cleaning method previously offered by blindguy.  If this was going to be my strategy I would clean thoroughly, then replace the IC, and I would take a resistance measurement from the solder-side to the shoulder of each pin on the IC.  Expect a low resistance.  High resistance means your cleaning has been unsuccessful. 

I don't suppose you're located anywhere near South Wales, UK? If yes I will happily meet up and help you save this AMIGA.

[Brian Hoskins]

The pins can be carefully sanded with a very fine grain sand paper if contact cleaner or WD-40 doesn't bring them up.

A fibre pen is what you want for this kind of work.  Like this:

https://uk.farnell.com/duratool/bu1019-1/pencil-brush-4mm-glass-fibre-scratch/dp/1421553

You can also get brass inserts for them but the fibre glass inserts are best for this particular application.

I notice you can also get them on Amazon, cheaper.

https://www.amazon.co.uk/Modelcraft-PBU1019-1-Glass-Pencil/dp/B002Z8IX36

[Brian Hoskins]

I'm in London so not a million miles away but still a fair old drive.

OK, let's see how far you can get over the next few weeks with continued advice from forum members.

If, by Christmas time, you're stuck in the mud we'll try to arrange something.  Do you reckon you could get over to a South West Amiga Group event? I've never been to one before but would be interested to attend.  We could contact them and ask if we can have a desk area so that we can setup your Miggy and get her going.

https://www.southwestamiga.org.uk/