on 8/9/00 10:22 AM, michael.conry@softhome.net at michael.conry@softhome.net wrote:

I am not sure if this is exactly on-topic, but i would be

very grateful of any

help you can offer. Basically, i think i have crippled

the scsi controller on

my boss's powermac 7200. (This occurred while trying to

hook up an external

scsi cd-writer to do some file movement to his new

machine. I turned the

burner on during boot, and also had it terminated. Both

these are no-no's for

the machine (although i am consoled by others that scsi

SHOULD be hot

swappable, and termination should not damage hardware).

Local mac expert could

not get it to boot off cd, so looks like controller is

knackered.)

Anyway, i have no access to other macs, and no way of

knowing if the hdd is

intact or not. What i do have is my linux box (Dell

precision 410) with

Adaptec 2940 U2W and Adaptec 2940 UW SCSI controllers on

the motherboard. I

know from reading around, that it should be possible to

mount the disk if i

can get it to work in the pc. what i don't know is how

safe it is to do

something like this (is the disk real scsi). Will i end

up with two broken

machines rather than one if i connect the drive to the pc

controllers?! Things

like the apple advice not to terminate external devices

due to the internal

hard drive being terminated do not give me confidence

(seems at odds with all

other scsi advice i have found).

I understand nobody can guarantee anything, but if anyone

subscribed to this

list thinks they know something relevant (like that i

should not even think

about this) then i would appreciate the advice. thanks michael

Michael,

Before declaring the 7200 dead, there are a few thing you might want to try. First of all the last external SCSI device and first internal hard drive must be terminated and all device in between unterminated. The external drive should not use an id of 0 or 3, 0 is for the internal hard drive and 3 is for cd-rom drive. Turning on an external drive while booting the computer usually will not damage the SCSI hardware but will corrupt the scsi driver on the boot disk, this will leave you computer unbootable an unusable. To reinstall the driver can be tricky. First, disconnect all eternal SCSI devices. Remove the cover top the 7200 and disconnect only the molex power connector to the hard drive, leaving the scsi cable attached. Start up the computer and insert a bootable CD, then restart the computer and hold down the 'C' key. At this point if the computer boots from the CD then all will be well.

If the computer stops with a blank grey screen and won't go any further then there is probably some damaged hardware. Try disconnecting the scsi cable from the hard drive and restart your computer. If you still get the blank grey screen then disconnect the cd-rom drive and restart. If you still get a blank grey screen then the motherboard is probably bad.

If the computer stops with a grey screen and a '?' in the middle of the screen, then the computer is looking for a bootable disk. Make sure that you CD-rom disk is a bootable cd and it has the Mac OS Installer program and Drive Setup program on it. If the computer still will not boot then you will have to get a bootable floppy to continue. You will need the Disk Tools disk for the 7200.

After booting you computer with CD or floppy and waiting for all disk activity to stop, plug the power for the internal drive back in. Wait 30 seconds for the disk to start up then launch the Drive Setup program located on the CD or floppy. The program will display a window with a list of drives, hopefully you will see two drives. One at ID 0, the internal Hard drive and one at ID 3, the CD-rom. Click on the the ID0 disk to highlight it then select the "Functions" menu and drag down to "Update Driver". If all is well the you will get a message "Your new driver will not be available until you restart.". At this point restart you computer from the CD and run the DiskFirstAid program. If the "Update Driver" option is greyed out and is not selectable then the disk was probably formatted with something other that an Apple utility. You will have to update the hard disk driver with a program like the FWB Hard disk tool kit or APS tools.

Bill Germer Computer Technician Shorecrest Preparatory School Saint Petersburg Fl