You should take it apart to see how are the caps and battery.
I do have question about the IIsi. I see many posts about IIsi ROM SIMMs, but my 2- IIsi 's have the ROM SIMM Slot but no ROM SIMM and there are to ROM Chips soldered on the bottom of the board (towards where the front of the machine should be). My question is, is this ROM SIMM necessary and what does it do? I remember the IIsi being 24Bit Dirty, so is the ROM SIMM makes the IIsi 32Bit Clean?
I do have question about the IIsi. I see many posts about IIsi ROM SIMMs, but my 2- IIsi 's have the ROM SIMM Slot but no ROM SIMM and there are to ROM Chips soldered on the bottom of the board (towards where the front of the machine should be). My question is, is this ROM SIMM necessary and what does it do? I remember the IIsi being 24Bit Dirty, so is the ROM SIMM makes the IIsi 32Bit Clean?