Help Needed - Mac SE/30 giving SCSI termination errors

[TheJ]

I have recently purchased a RaSCSI for a Mac SE/30 that I have successfully re-capped.
The hard drive had died (or maybe not?) so the RaSCSi was to be it’s replacement but I can not get it to work. I keep getting the “Bus not terminated” error in SCSIProbe.
I'm booting into system 7 from a BMOW ROM to do these tests.

I connected the RaSCSI to another Mac SE/30 and it works perfectly fine there. (only item on the bus in both cases)

I connected a Zip drive (with termination switch ON) to the first Mac and SCSIProbe still reports “Bus not terminated”.

I checked / tested the fuses and the diode beside the SCSI connector on the MoBo and everything appears fine.
I checked the pins on the SCSI chip. There is a small amount of corrosion but all the pins look solid.

What else can I test???
What could be causing the termination error??
I don’t have a sonic cleaner but I’m seriously considering getting one.


J

 

[JTRetro]

I have a board that I just recapped with the same problem. I tried re-flowing the solder to the SCSI chip (the NCR 53C80 PLCC)...and still no luck. My guess is that the SCSI chip is bad and needs to be replaced....and that could be the same with your board too.


It would be wonderful if it was as simple as a bad resistor value or something......but I'm not sure.

 

[eric]

Are both termination switches on the RaSCSI terminators on? (simple thing, but easy to miss)

 

[TheJ]

Are both termination switches on the RaSCSI terminators on? (simple thing, but easy to miss)

@eric Yup, my termination switches are both on. In fact, my RaSCSi had a bad switch so I removed the switches and jumpered them. Works on another system but not on this one :-(

@JTRetro I tried the same thing. Removed teh chip, cleaned it and the pads and soldered it back on. Same issue.

I was hoping to get a conversation going on how other's solved their SCSI problems.
Anyone have a Success Story ?!? What worked for you?

J