Macintosh Plus with Weird CRT startup


Hi all,

2 wierd things:

  1. My Mac Plus on startup is initially showing the correct 2 icons but seems to be missing the greyscale background - i.e. the question mark followed by happy mac when a proper disk is inserted.
  2. After the happy mac symbol appears, nothing happens after that - it remains … er … Happy!

I have attached screenshots of the two symbols and also a third of a normal mac’s screen in comparison - any ideas?
at boot

People probably remember my original post about reflowing the power supply board.


after disk insert


Normal boot screen from my other mac plus below


No help again, sorry, but by god those are smart looking Plusses!


All right, as embarrassing as it sounds I found the issue … I was cleaning the memory chips and putting them back in when I found out that a resistor on the logic board been knocked out. A little bit [sic] of solder later and its fixed. Screen is grey again and everything boots properly.

Thank you all