Q700 and SCSI Hell

[fhaber]

So, newbie here. I'm a techie, mostly PC, but do have an iBook 05 and a nice, working IIci. I work with Macs regularly.

I've been given a Quadra 700/20MB/320MB. Since I know the insides of the IIci, the insides of this are not exactly unfamiliar (g).

This thing had a Reply card, which I immediately pulled while I played. I have no need for it. It actually mounts a Cyrix 486 clone!

Problem at hand: rapidly failing internal SCSI, no matter what I do. The machine ran well for a good while, and I was well on my way to customizing it and putting in a bigger HD. Then tragedy.

Background:

Careful inspection shows no leakage from any surface-mount caps. Are there standup electrolytics somewhere? Do I need to pull the board and look at the bottom?

The system board looks glossy and happy; there isn't even any dust. PRAM battery is new.

The beast booted and ran fine for a day. Now it boots one of ten times from HD.

What I've done:

o New ribbon cable.

o Tried a spare 1G SCSI drive that boots fine on the IIci. Same old.

o Tried termination on and off, parity on and off, one drive and two.

o When boot fails, I do get the brieff flash of each HD light as the bus probes all the SCSI IDs, forever, but nothing beyond that. I get the usual death chime and the f-over-d code from the ROM monitor when I hit the boffin-button.

o All drives spin up and make normal recal noises.

o 5V and 12V are within 3%.

o The machine boots reliably from the superdrive, which seems smooth after a bit of silicone spray.

o I have only Norton DD3 on floppy, and that doesn't detect an HD, needless to say. It will see an "unknown SCSI at ID 0" if you select the deep probe from the pulldowns. It won't scan the drive, or even home it.

o Resetting PRAM helped some initially, but things seem to be getting sicker with each boot.

o My IIci, once I installed a 4G wide Atlas with wide-narrow adaptor (low ID term physically separate from that on the unused high bus IDs), got cranky at boot, too. I now have to have either a terminator on the back of the machine, or an external chain (CD, Bernoulli, ext. HD, etc.) attached, with term on that.

o Hints? Anyone have a NuBus SCSI card for cheap in the Eastern US?

 

[Dennis Nedry]

What about external SCSI? Do you have an external SCSI CD-ROM that you could try booting from? I would be convinced that you have a SCSI problem if a boot CD acted the same way.

 

[fhaber]

I have no bootable Mac CDs, except my Tiger one. I don't even know what a bootable HFS CD consists of. My IIci barely handles CDs in common/ISO format - it's very flakey, and needs the third-party CD toolkit to work half-well.

I installed Sys 7(.5.x) on the IIci from floppy IMG via FTP.

Are there Iomega tools to make a Mac-bootable 100MB disk? I do have an original SCSI external Zip drive (the one that switches between ID 5/6, the real SCSI one) and a Bernoulli 150.

 

[Dennis Nedry]

Even if a CD-ROM drive normally requires some non-Apple driver, it should still be able to boot your Mac. It's kind of counter-intuitive. So long as the CD is bootable, it should boot your Mac in nearly any CD-ROM even if sticking it in after it's booted some other way does not produce an icon on the desktop.

It's possible that there is a hardware problem with your hard drive(s) and also there may be a problem with the software on them. It is possible that the same hard drive will work in one Mac and not on the other and for there to still be nothing wrong with the SCSI bus.

I recommend trying other SCSI devices to see if the problem is consistent across all SCSI devices, or only is affected by some of them. If you hook up a SCSI CD-ROM and boot the Mac with it consistently well, I would say there's nothing wrong with your SCSI bus, and your focus should be shifted to the drives themselves. I believe this is the next logical step to take.

The Quadra 700 was built to be an especially durable computer. I don't think it has ANY electrolytic caps on the logic board. I would tend to suspect any other part before the logic board.

You should be able to find a bootable System 7.1 - 8.1 CD image somewhere if you look around. If you burn this with Toast, it should be able to boot your Mac if the SCSI bus is working, regardless of the obscure brand of CD-ROM you may be using.

 

[Charlieman]

A great diagnosis, fhaber. You didn't say which formatter you used for the hard drive, but that may well be unimportant.

Can you pop SCSI Probe on a bootable floppy and see if it can identify the hard disk. Version 3.5 onwards should work in a Q700.

 

[Flash!]

I have no bootable Mac CDs, except my Tiger one. I don't even know what a bootable HFS CD consists of. My IIci barely handles CDs in common/ISO format - it's very flakey, and needs the third-party CD toolkit to work half-well.
I installed Sys 7(.5.x) on the IIci from floppy IMG via FTP.

Are there Iomega tools to make a Mac-bootable 100MB disk? I do have an original SCSI external Zip drive (the one that switches between ID 5/6, the real SCSI one) and a Bernoulli 150.

If the ZIP disk is inserted at bootup, the Mac should 'see' it without and special drivers. So plug in ZIP drive, insert disk, then boot up from a floppy - once booted up you can either copy the system from the floppy to the ZIP, or do a full install if ou have the complete set of install floppies. Once a system is on the ZIP disk, in the absense of any other suitable SCSI boot disks, you should be able to boot up the Mac

note: you don't need iomega disk tools or drivers until such time as you have a working internal boot disk. All it does is enable you to boot up without a disk inserted in the ZIP drive, as i said - if the disk is inserted before boot then it *should* mount with no problems at all.

 

[Bunsen]

And the prize for most thorough newbie diagnostic before crying halp goes to ...

I have no further suggestions than what you've come up with yourself, and what others have shared here. You should be able to find a boot/install CD of System 7.6.1 or Mac OS 8.1 on ebay, or as suggested, *ahem* elsewhere. If that fails to boot with proper termination, then as you've already deduced I think a Nubus SCSI card is your next step. That will give you faster SCSI performance as well.

 

[macgeek417]

Have you tried changing the SCSI ID??? No clue if that would help or not as I have no idea what i am talking about...