made a disaster don't know what happened!  probably a screwdriver on the table shorted something on the hard disk i'm not sure, there was a little smoke.

switched off, now if i connect the power to this drive the mac produce strange ripetitive sounds and won't boot,quite black screen , but only with floppy it's all ok.

If i connect only the 50 pin without power the mac works good. I'm a little worried about having damaged the scsi interface... but if i connect the adapter and the drive which i was talking this thread:   https://68kmla.org/forums/index.php?/topic/26483-macintosh-se-80-pin-scsi-hd/ seems all good except that that drive is not compatible and i can' t test really anything!! what do you think it' s possible i damaged the 50 pin interface?

I don' t care so much about the quantum i' m a little worried about the motherboard...

EDIT  tried to connect the quantum to a pc power supply and it literally stops it like it do on the mac! there' a visible burnout chip L2722 st88942