Accessing CIA chips in Amiga 3000 and 2500?

[HolySamosa]

First post here.  :-)  I'll try to follow up with a proper introduction in the Introductions forum.

Any suggestions on how to access the CIA chips in an Amiga 3000 without completely disassembling the the machine?

While I'm at it, also on the 2500?  I'm thinking perhaps I can access them after removing the power supply...

Thanks!
Jeremy

[HolySamosa]

Thanks for the reply, Mike!

I do have Band-Aids handy. :-)

As for why I'm trying to get to the CIAs, I have collected an A1000, A2500 and an A3000.  All of which malfunction in some manner, a couple of which may be due to CIA issues.  I was hoping that a little chip swapping between the three might help me diagnose the issues and perhaps get at least one up and running:

• The A1000 gives a dark gray screen at power on.  Doesn't get to Kickstart. Reading online suggests this could be a CIA issue.  I did try swapping the positions of the CIAs in this box with no change.
• The A3000 generally works, however it will lock up fairly often when trying to access the disk-- either floppy of hard drive.  Readings suggest this is a CIA issue.
• The A2500 hasn't been well cared for.  Can't immediately recall if it makes it to Kickstart, but it throws Guru Meditations.  Don't recall the order, but I did make note of these: #00000008.00202FDEm #00000004.00000000, #00000004.00202FDE, #0000000B.00001970.

Think I'm on the right track with the CIA swapping?

I lusted for an Amiga as a kid in the 80s and never could get one.  Better late than never, eh?  Now I just have to get 'em running!

Thanks!

[HolySamosa]

Haven't got a visual on the 2500 battery yet.  The 3000 battery is leaking and there is a small amount of corrosion in the surrounding area.  Doesn't look too bad.

[HolySamosa]

Thanks again for the advice.  Hopefully I'll get a chance next week to pull the motherboards from the A3000 and A2500 and unsolder the batteries and perform some other checks.  

I now have the A1000 powered back up and have a better description of it's behavior-- I'll start a new thread to keep things strait.

Thanks!