An update... since I had the SE/30 taken apart while researching for another project, I decided to check the SCSI chip connections according to
the drawing I made -- this is my SCSI-less SE/30, and I want to get it in full working order, as you may deduct from my previous posts.
Guess what? The already suspicious DB2 line was the only broken connection! So maybe the 53C80 is not dead...
Then I decided to hook up a CD300e drive externally, while making a jumper between the DB2 line on the (now empty) internal SCSI connector and the relevant pin on the 53C80. Thanks to a garden variety ATX extension cable (with the rightmost 6 pins unused), servicing the SE/30 becomes unbelievably comfortable, why didn't I think about that before? :'( And it makes holding the jumper by hand, at least, feasible for a quick test.
Can you imagine my expression of joy when I saw the CD's LED flashing (loading the driver), then the Happy Mac, then the Welcome to Macintosh screen? 8-o It didn't boot all the way because the bootable CD at hand was for a Performa 5260, thus incompatible with the SE/30 but what the heck! SCSI is working!
I'm afraid the SE/30's board is multi-layer, and trying to find any flaw seems very difficult... but I can always place a permanent jumper on it. In the meanwhile, I've been advised to put some heat with the iron on the PB2 solder point of the internal SCSI connector, just in case it reflows properly thru all the layers. The connection between the internal and external ports has been checked perfect, BTW.
;D ;D ;D
the drawing I made -- this is my SCSI-less SE/30, and I want to get it in full working order, as you may deduct from my previous posts.
Guess what? The already suspicious DB2 line was the only broken connection! So maybe the 53C80 is not dead...
Then I decided to hook up a CD300e drive externally, while making a jumper between the DB2 line on the (now empty) internal SCSI connector and the relevant pin on the 53C80. Thanks to a garden variety ATX extension cable (with the rightmost 6 pins unused), servicing the SE/30 becomes unbelievably comfortable, why didn't I think about that before? :'( And it makes holding the jumper by hand, at least, feasible for a quick test.
Can you imagine my expression of joy when I saw the CD's LED flashing (loading the driver), then the Happy Mac, then the Welcome to Macintosh screen? 8-o It didn't boot all the way because the bootable CD at hand was for a Performa 5260, thus incompatible with the SE/30 but what the heck! SCSI is working!
I'm afraid the SE/30's board is multi-layer, and trying to find any flaw seems very difficult... but I can always place a permanent jumper on it. In the meanwhile, I've been advised to put some heat with the iron on the PB2 solder point of the internal SCSI connector, just in case it reflows properly thru all the layers. The connection between the internal and external ports has been checked perfect, BTW.
;D ;D ;D