Amiga 3000 Locks on any SCSI on boot.

[matt3k]

I have a A3000 that give a solid yellow light and locks the system when you turn it on.
With no drive on the bus it boots from floppy just fine.

Here is what I have tried:
* Tried different SCSI, ramsey, and dmac chips
* Tried removing terminator resistors on mb.
* Tried many different drives.
* Tried adding mutiple drives to chain.
* Removed battery to lose NVRam settings.
* Turned off all options in nvram.

[pipper]

Are you mixing static column and fast page mode ram? If so, try moving FPM ram into the first bank. This way the OS will setup ram access for FPM mode.
Did the same machine run before and the issue appeared out of the blue?

[matt3k]

Originally Posted by pipper

Are you mixing static column and fast page mode ram? If so, try moving FPM ram into the first bank. This way the OS will setup ram access for FPM mode.
Did the same machine run before and the issue appeared out of the blue?

It is a 3000T and I tried it without any fast zipp memory. Right now it has 60NS static column.

So since I didn't have any fast memory, think memory isn't it unless it is the chip memory with is zipps in a 3000T.

I removed the accelerator and the problem began. I was using the 3000 SCSI bus with the accerlator.

Tried with and without the 74F08n chip and different jumper settings.

[r.cade]

Bad cable, bad termination, incompatible or bad drives.

I've also seen Kickstart versions cause this. On one of my A3000's, 2.04 works fine with most drives, 3.1 will lock up like yours with some drives and not others.

It's possible to blow a diode on the desktop A3000 board that will cause issues with termination on external drives, but not sure on A3000T. I haven't had to repair enough of those to see that problem.

[patrik]

Originally Posted by r.cade

It's possible to blow a diode on the desktop A3000 board that will cause issues with termination on external drives, but not sure on A3000T. I haven't had to repair enough of those to see that problem.

Yes this is a valid check to make - measure that you have termination power on the SCSI connector, else all separate terminators and many terminator-on-hard drive will fail to work. Exception being those on harddrive powered internally from the harddrive.

The A3000 internal termination resistors are powered from internal +5V so would have worked even if the diode was blown, but you said those were removed. However, it is great to have them removed anyway as it makes it possible to have both internal and external SCSI devices connected with correct termination - the onboard would else terminate the middle of the chain.