macintosh rom simms

Every Macintosh from the II forward (well, probably not the Classic) was built with a ROM socket. However, the vast majority of them have ROM chips soldered to the board, and the socket is only there for updates which were never deemed worthwhile. Unless you have an incredibly rare Q700, there are ROM chips soldered to the board. They'll have a part number something like 343S0xxx or 341S0xxx and there will probably be four of them (each with its own, probably sequential, number), although there might only be two if they used 16 bit wide chips. I'm not sure if the Q700 is recent enough, but at some point they moved to 44 pin PSOPs for almost all their soldered down ROMs. Symptom of a missing ROM would be that the machine powers up just fine and all the drives spin up, lights come on, but there is no start-up bong and never any video from the monitor output. If the machine fails to power up all-together, then you have a different issue than lack of ROM. If you have a power supply failure, the power supplies from the IIcx, IIci, IIvi, IIvx, Q700, Centris 650, Q650, and PowerMac 7100 will work in the Q700. It was a long-lived power supply model. Jeff Walther