A2000HD Battery Fun

[Castellen]

Most likely there will be a lot of corrosion on the 68000 socket contacts causing bad connection with the CPU.
The only way to fix it properly is to replace the socket.
Simple enough if you have reasonoble soldering skills.  The easiest way is to heat one leg at a time from the bottom of the board, and pull the pin up through the socket.
With removing the pins one at a time like that, there is less risk of damaging PCB tracks.

For the replacement socket, use one of the slightly more expensive machine pin contact ones if you can.  Not the cheap'n'nasty dual wipe contacts C= decided to use.

[Castellen]

@ Darklight
For a replacement socket, you should be able to get one fairly easily from most professional electronic component retailers.
Start with Altronics/Dick Smith, but they probably won't have that size.
Farnell or Radio Spares probably will, but I think minimum order value is $20 or something.
You've got way more electronic shops in Aussie compared to us, so shop around. :-)

Don't use a 2nd hand socket.  For a start, you don't know the condition of the contacts inside.  Plus the best way to remove a socket soldered into a PCB is to completely wreck it.  To unsolder it you heat each leg one at a time from underneath and pull out the contact from the top.

To answer the question about corroded PCB tracks, it's possible some tracks have been corroded, but it's more likely that the 68000 socket is the main culprit.
The tracks in the A2000 are fairly thick and wide, so it takes a lot to damage them.
Problems usually occur in vias (the wee holes which make tracks join top and bottom PCB layers).  The battery chemical runs down inside the copper plated via hole and corrodes it.
I've illustrated it here:
http://amiga.serveftp.net/images/ViaRepair.jpg

It's a good idea to use a multimeter to check the continuity of tracks which have vias running near the battery area.
Can't quite remember, but I think the A2000 has the vias where the hole is filled with solder??
These are quite good, as the battery chemical can't run down inside.