Differential diagnosis of a blank screen on a Commodore (I'm a med student :-) ------------------------------------------------------------------------------ If the screen is *black* your first suspects, in order, are the PLA and then the VIC-II. Also, as always, check the fuse. I'm guessing that the blank screen you get is a *white* screen and possibly a cyan border? If cartridges work, as they do in yours, the problem is clearly one of the ROMs. Since the disk drive is operational my first guess is the BASIC ROM, which is fortunate for you because the Kernal ROM is unique to the SX :-) I don't remember the number on it, though, but the SX Kernal should be labelled 251104 with possibly a revision number (-04?). DON'T swap that one out. The BASIC ROM is probably labelled 901226 but that's in the breadbox systems. You can take that from any regular C64, and it should work fine. If both ROMs are shot, all is not lost if you have an EPROM burner -- see this wonderful archive: http://www.funet.fi/pub/cbm/firmware/computers/c64/index.html Just my $0.02! (You adjust for AUS$.) -- ----------------------------- personal page: http://www.armory.com/~spectre/ -- Cameron Kaiser, Point Loma Nazarene University * ckaiser(a)stockholm.ptloma.edu -- Mickey Mouse wears a Spiro Agnew watch. ------------------------------------