Apple IIc going crazy, bad ROMs ?

[Gabriele72 <Arel72togli_questa_parte@email.it>]

Hello,

my attempt to revive an Apple IIc ended in a comatose unit... perhaps 
someone here may point me in the right direction to fix it.

The machine powers up with the usual Apple //c [...] Check Disk Drive 
writings but also some "@" appear on the screen here and there. Despite 
what I throw in the disk drive, the machine always ends up in system 
monitor.

Breaking into basic prompt is possible but basic commands return weird 
effects (the commands give the expected result followed by load of 
garbage characters). I suspect one or more bad ROMs but I can't verify.

I noticed 3 socketed ROMs, 342-0133 CHARGEN (I think it's fine), 
342-0284A MAP, and 342-0272 MON. I can burn 2716 EPROMs and up if 
needed. Any suggestion is greatly appreciated.

*Gabriele*