Hi all! I finally got a compact mac back in my collection! (I used to have about 30 compact macs, but gave them all away after a flood did it's worst on most of them. :(
I now have an SE/30, imo the prettiest of all of the compacts... It worked okay when I got it, no sound though. I put a drive in, installed 7.1 on it and then the SCSI chain stopped responding. I figured it was caps, so I replaced all of the capacitors with modern ones of the same value. Sound returned, and it booted up fine... from floppy. To check things out, I did try the hard drive and scsi cable on another board (I have a few SE mainboards lying around, so I dropped one in. I checked connectivity on the board against schematics as well as test diagrams that people have made... So here are the symptoms: SCSI Drive does not function either on the internal or external chain connectors with appropriate terminaton (doesn't work without termination either... i had to try it. ;) SCSI Drive is known working (tested with SE motherboard) SCSI Cable is known working New battery on the board Power Supply outputs expected voltages Appropriate power appears on drive connector, as well as on SCSI header Fuses are ok on the board. inductors are ok as well. SCSI controller chip's 44 pins were continuity-tested to their appropriate connections on other chips or the SCSI headers All pins from the internal 50 pin header do connect to the correct locations on the DB25 external connector No shorts were found on these headers. Apple HDSC Utility shows no SCSI drives present Hacked Apple HDSC Utility (for non-apple branded drives) also shows no SCSI drives present SCSI probe complains that the chain is not terminated. Termination power is present on both SCSI connectors. (4.7 volts, approx) I jumpered across to give it the 5.02 volts measured on the floppy port, thinking 4.7 wasn't enough, but that did not change anything. I'm at a loss at this point. About the only thing I can think of is that the 53c80 SCSI chip is faulty... that seems to be the only place left for a fault... Thoughts? -- -- ----- You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To leave this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/ --- You received this message because you are subscribed to the Google Groups "Vintage Macs" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
