68kMLA Classic Interface

This is a version of the 68kMLA forums for viewing on your favorite old mac. Visitors on modern platforms may prefer the main site.

Click here to select a new forum.
Missing -12V voltage on SE/30
Posted by: macintosh2002 on 2024-08-04 10:25:57
Hello, I recently recapped this SE/30 board and it works - I got the chime, the mouse pointer appears and the blinking question mark too. On J12 pin 7 there is -11,7V, C9 negative side also -11,7V - but not on floppy port pin 5 - here my DMM is jumping around and goes crazy!?!
I also have solid +12,65V and +4,95V.

Where can I find the issue, can someone maybe point me in the right direction please?

Thank you🙂
IMG_9347.jpg
Posted by: dochilli on 2024-08-04 12:08:53
The SE/30 has no -12V at the floppy port.
Posted by: macintosh2002 on 2024-08-04 12:42:26
The SE/30 has no -12V at the floppy port.
you're right, thank you! Then this board is in full working order, I was just surprised and had the -12V from the Classic board in mind...
1