Author Topic: A3000 Rev 7.3 mobo SCSI problems (Read 1869 times)

stevee617 · « **on:** January 23, 2011, 05:06:39 AM »

Did the A3000 Rev 7.0/7.3 motherboard have the backward diode issue?

I have an Apple CD-600e connected & terminated and the computer just sits there with the HD light on and does nothing.

I shut down, turn it off and turn off the CD-Rom, switch the computer back on and it boots right up.

Any ideas?

stevee617 · « **Reply #1 on:** January 23, 2011, 04:17:57 PM »

Yep, It has the -04 SCSI controller chip in it. Guess I need a -08 SCSI chip.

stevee617 · « **Reply #2 on:** January 23, 2011, 04:24:12 PM »

Amiduffer stated:

"Re: A3000 Rev 7.3 mobo SCSI problems
I think you're confusing the problems with some of the C= 3640 accelerators which had the problem with reversed caps.

Make sure that the CD and HD have different unit numbers and that your HD isn't terminated.
__________________
Amiga 3000D UP and running! Hear that clicking.

Amiga 3000D & 4000D in storage sadly. "

No, there was an issue with some motherboards with the SCSI termination diode, which supplies 5 volts on Pin 25 of the external SCSI port. The diode is installed backward. To make matters worse, the silk screen on the motherboard was even print incorrectly.

I am unsure which motherboards were affected by this.

stevee617 · « **Reply #3 on:** January 23, 2011, 09:11:38 PM »

All the on board terminators are removed. The CD-ROm is terminated as well.

I just verified that the CD-ROM is bad, so I think that solves my problem.