Amiga 500 IC issues

[Tenacious]

Multimeters are cheap.  If you know how to use it, never be caught without one.  I would suspect the PS until it's proven.

Examine the pins of the square chips to see if all are correctly formed.  If one is abinormal, gently bend it like its neighbors.  Don't overdo it.  Same with the dips.

Don't GeorgeBush the Atonce!  I'd be interested in buying or trading for it if it has no use to you.  I have spare 68000s and other options.  Let me know.

[Tenacious]

Might be prudent to pull and inspect PLCC chips last, unless you're very experienced doing this.

As for the dips, I usually pry a little at each end with a screw driver.  If I work slow, in 5 or 6 passes the chip comes out without a bent pin.

Maybe the problem is with the power supply after all.  How many amps is the 5 volt rail rated for?

Do you intend to expand this 500?

[Tenacious]

You lost me on the bottom shielding.  I'm talking about gently prying the chips (dual in-line pkgs) up out of their sockets.  This will be required to fully get the cleaner between the pins and mating sockets.  

Some industrial contact cleaners are harmful to plastics and other materials (not to mention ppl).  I've never had a problem with Tuner cleaner from Radio Shack nor with isopropyl alchohol.  You want stuff that evaporates quickly and leaves no residue.  Tuner cleaner is also electrically non-conductive.

Commodore actually made 2 versions of the Amiga P/S brick, yours is the more desirable version.  The other was rated for only 3 amps on the 5 volt supply. BTW, there are hacks on Aminet to convert old XT P/Ss for Amiga use.