Definitely reseat the chips. My A500 has a chip come loose every time I move it. One of the CIAs has DF0: selector mod that uses a machine socket for the CIA to sit into on top of the mod's PCB. Without fail, if I should pick the 500 and move it, this comes just slightly loose, and the machine will not boot. I open it up, reseat it, and, it boots like a champ.
