Chosen Solution

Does all this sound correct this system does not work? Analog seems to be 120/240V international MACINTOSH 630-0108 1983-84-86 it also has an orange sticker that says 630-5289 240V but the board still has w12 still installed.The analog cover has 120V with W12 still in place checked

Logic is a 820-0174-c 1986 630-4122-[|||||]

The computer is a MACINTOSH PLUS 4MB 120VACMONITRON Taiwan R.O.C 157-0042ATell me if all of this sounds correct?Also, what does R10 on the log board used for?

Bobby Gunnels  this is a bit of a confusing question. Let’s see if we can straighten this out. Analog seems to be 120/240V international MACINTOSH 630-0108 1983-84-86 it also has an orange sticker that says 630-5289 240V but the board still has w12 still installed. The analog cover has 120V with W12 still in place checked 630-0108 is a 120/240 V powerboard. To operate on 120 volt, W12 must be in place. For 240 Volts it needs to be removed. Logic board is a 820-0174-c 1986 630-4122 The computer is a MACINTOSH PLUS 4MB 120VACMONITRON Taiwan R.O.C 157-0042A All of that sounds correct. Also, what does R10 on the log board used for? We would need to see what you are referring to by R10 . Reference designators starting with a “R” are resistors. If the issue here is that your Macintosh Plus does not start you need to start checking things out. The number one thing you need to do is to recap the logic board and replace all other capacitors. Check the board for damage and corrosion. Watch the CRT, they are packing a punch and in the best case scenario will only knock your socks off! I have a couple of those that I totally disassembled, cleaned and recapped which then started to work properly. Your question is just the beginning “this system does not work “ and you need to start to diagnose. Post some really good pictures of your boards etc. with your QUESTION so that we can see what you see and possibly help you out. Adding images to an existing question

this may be a capacitor issue do any cpas look damaged to about to blow? or have any already gone? also the loud thump may be caused by the flyback failing. overall a new analogue board may be needed