Thanks again to Stephen for sending me a set of replacement ROMs (completely free!). I have 7 compact Macs of various types, but one of them has never worked since I received it -- a Mac Plus. I was able to confirm that the ROMs were the culprit a while back by swapping in some known good chips...
I found a "Mac Bottom" on eBay recently for a fairly reasonable price. I don't have an external SCSI hard disk, so I thought I would take a chance on it, even though the seller didn't really seem to know whether or not it worked. When it arrived, the fan inside had broken free of its moorings...
I'm not very knowledgeable about capacitors, but here are some photos of my boards if it will be helpful (I also have one more that I can't find at the moment). One of mine is a Japanese board and one is American. I don't see anything else that looks like a capacitor to me.
I did try swapping the RAM earlier but neglected to mention it. But I've never taken out a Mac's ROM chip (and wasn't even sure if they were socketed until I checked which ones they were). After doing some swapping around of chips, I can say that it is definitely the ROMs that are at fault. When...
How did this work out for you? I’m wondering if a problem I’m having with two of my Mac Plus units might not be related to the ROM since the symptoms seem similar and I’ve narrowed it down to a logic board issue.
I don’t think I actually tried it before, but yes the logic board from the good machine does work in the bad machine, so it does look to be a logic board issue. I haven’t tested voltages because I don’t really know how, although I do have a multimeter.
I guess what I want to know is if...
Sorry if I gave any inaccurate advice. When I installed my SCSI2SD in my SE/30, I did use the adapter and it works fine, so it's not as though having it will be an issue. But if you can save a little money by not buying one that would obviously be better. Should OP just give it a try without it...
The cable you're talking about provides power to the hard disk, and you will need an adapter for it. As for the CRT, just waiting for it to discharge can be problematic since it can take quite a while and there's no specific time beyond which it is definitely safe. But if you're just attaching...