[sdiy] OT scsi testing

[Microtonal]

Assuming you made no configuration changes to your system right before the
errors began occurring, then it's probably a hardware problem.
Unfortunately, since you have only two SCSI devices, the Mac controller and
the CDR, it's not easy to narrow it down between the two.

I don't use Macs, but I would guess they come with the SCSI terminators
enabled for the host controller.

The "sense code 0x29: Power On, Reset, or Bus Device Reset Occurred."
message is telling you that the controller saw something it didn't like on
the bus, probably a SCSI bus hang.  This can occur due to noise on the SCSI
control signals.  If this is the problem, yours occurs so rarely that I
doubt you could capture the noise on an analog scope.

If you want to take a stab in the dark, I recommend the following:

1.  Look for cold solder joints or lack of solder on the host SCSI
controller and the CDR SCSI controller, connectors and terminators.  These
will be right next to the SCSI connectors.  They're probably PQFPs.
Particularly look at the SCSI control lines, REQ, ACK, SEL, etc.  I've seen
these parts with pins laying on the surface mount pads and NO solder on
them.  Works 99% of the time, too.  If they're intermittent, ohming them out
won't do any good, you're likely to push the pin down to make contact when
you do that.  A dental pick is handy here to pry at any pins to see if they
"give" and aren't really soldered down.  Touch up any suspicious, hazy
looking solder joints.  Also look for solder bridges or loose pieces of
metal, you will need a microscope or damn good magnifier for that.

2.  If this doesn't help, you might have a CDR problem upstream of it's SCSI
controller.  Best way to test this would be to buy a CDR from a retailer
that offers an unconditional 30 day return guarantee.  If the replacement
CDR works then you needed the replacement after all.  If it doesn't, then
you have a host controller problem, or maybe some subtle
software/driver/configuration problem that just happened to bite you in the
a** when it felt like it.

John Loffink
microtonal at worldnet.att.net

----- Original Message -----
From: "Dave Krooshof" <krooshof at xs4all.nl>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Thursday, July 26, 2001 8:20 PM
Subject: Re: [sdiy] OT scsi testing


> >Could be a temperature problem. Is your burner toasting itself? How is
the
> >air flow around the burner?
> It has a built in vacuum cleaner. When I switch it on, it's both airco and
> toaster. Man, the thing is noisy, but not hot at all.
>
> >Is each end terminated ONLY?
> How do I terminate the Mac end? Never heard of this, except you and Paul
> Maddox mentioning it now...
>
> >What is the termination type (passive, active, forced perfect)?
> I tried 2 things:
> 1. the onboard termnination switch, which sets a jumper on the
> toaster itself. worked for 2.5 years.
> 2. A terminating plug I bought when I ran into troubles.
> No difference, except when I take em both of, obviously.
>
> >Other SCSI devices?
> Nope.
>
> None now, to be exact. The thing just DI(Y)ed itself.
> I just connected it internally. Opened the CDDA application for a test
ride
> in s(t)imulation mode. As soon as it started 'writing' it hung up big
time.
> restarting... it didn't boot... disconnected the cdr... restarted...
> retarted...
> restarted again... I'm glad it's up again. So far for my tonights yamaha
> cdr400
> experiments. Never liked their synths either.
>
> Still the question remains... Is this my Mac, or my cdr being screwed up?
> This question is a bit of a pain, as these Dutch stores won't let you buy
> things to test...
> And eh, If I were to buy a new toaster, it's bound to be unsupported by
> Masterlist 2.0 (professional audio cd mastering software)
> A new copy will cost me some 700$. That's a grand in total.
> Bad mood.
> But it's kind of a relief not having to run any more tests on the
machine...
>
>
> Dave
>
> ----- >^v< ---------------------------------------
> Dave Krooshof http://www.xs4all.nl/~krooshof
> geluidstechnicus @ http://www.ahk.nl/the
> webmaster: http://www.popronde.nl
> -------------------------------------- >^v< -----
>
>
>