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User profile for user: Deborah Terreson
Deborah Terreson Author
User level: Level 4
1,071 points

Bus Error At Startup

Okay, this one's got me scratching my head.

My brother has my old G3 with a Sonnet G4/500 ZIF, 448MB RAM, OS9.2.2, two hard drives and an ATI Radeon 7000. It started acting funky after he fell asleep and left it on all night. This morning, he got the bomb on the reboot with a bus error message and tried to start it but it wouldn't. Then while it was booting again, it told him the disk was unreadable and asked him to initialize - so he did and toasted his storage partition and lost all his music files. Bummer. He dropped it off here earlier and I can't make heads or tails of what's going on.

I got it to start once and the slave drive wasn't mounted. The second time I started it, it locked at the Mac OS window, so I tried the force re-boot keys (cmd controlpower), and I got a blank rectangle with the '>' symbol in the upper left corner. Never seen that one before.

I had to shut down by unplugging it from the wall.

On the last time through, I got the startup chime, then nothing. I am at a loss here.

My thoughts may be one of the data ribbons to the drives.. they are the original Foxcom kit that came with the machine, and one was a bit crimped.

I'm thinking it may be that? Considering that I did add the ATI card and more RAM last week and I cleaned out the prodigous dust bunnies that had accumulated inside it - and the fact that the slave drive did get brained..

Would that cause a system bus error?

Deb.

BeigeMT Rev.3, G4/1.0ghz ZIF, 768MB RAM, 80GB HD + 160GB Ext. USB, Mac OS X (10.3.9), Radeon 9200, Wacom 12x12, USB2, SCSI CD-RW, DVD-R, Epson740

Posted on Mar 21, 2007 11:55 AM

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13 replies
User profile for user: Sean Clancy
Sean Clancy
User level: Level 1
105 points

Mar 21, 2007 2:06 PM in response to Deborah Terreson

I've personally had system bus errors caused by damaged ribbon cables and/or PCI and Personality (PERCH) Cards not being fixed in their slots.

I would reseat all the cards first and then replace all of the SCSI and IDE cables.

Also, blowing some canned air in the empty PCI and PERCH slots might be helpful to remove any dust interfering with the contacts.

Good luck.

Sean

Beige G3 300AV MT; 768MB RAM; Acard AEC-6280M ATA133 PCI; Maxtor 6Y080P0 80GB; Mac OS X (10.3.9) Generic Firewire/USB2/Gigabit PCI
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User profile for user: Grant Bennet-Alder
Grant Bennet-Alder
User level: Level 10
126,979 points

Mar 21, 2007 2:29 PM in response to Deborah Terreson

Bus Error on a Mac that was working tells you that bad stuff was executed from memory. Determining he source of the bad stuff is the mission to be accomplished.

First, Reset the PRAM and check the battery for 3.1 Volts in-circuit with the AC power removed. If less, you may choose to remove it for bench testing and plan to restore it when otherwise working. Make sure the sound card is completely seated -- it tends to dance part way out of its slot and can preclude booting.

Next, bypass the Hard Drives and all the data on them by booting from a CD. Problems with an image from a CD indicate more fundamental problems, like memory problems. DIMM First Aid can be helpful to read out the configuration of each module and check that it is correct. If memory problems are indicated, a more thorough memory test may be needed, or methodically shifting the memory modules down one slot and trying again can sometimes isolate a problem module.
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User profile for user: Allan Jones
Allan Jones
User level: Level 9
68,600 points

Mar 21, 2007 2:22 PM in response to Deborah Terreson

Hi Deb,

There are several things to check and you're on one already. Ribbon cables can go bad. The one that seems to go more often is the CD ribbon. Of course, any crimped cables raise an alarm,

The only time I've gotten a bus error on my Beige was after I installed the ZIF upgrade. Apparently I had failed to properly seat the ZIF card when I installed it. I reinstalled it using a little more downward force than the instruction called for when I rotated the lock lever. The reseat fixed it.

Also check that the personality card it. If one end loosens a little, it can make the computer go nuts.

Did we mention PRAM battery? Worth checking if it's never been replaced.

I'd do all the diagnostics with the slave drive removed or at least disconnected from both power and its ribbon. If you get the beast running, then add the slave and see if that trips the barmaid.

Allan
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User profile for user: Deborah Terreson
Deborah Terreson Author
User level: Level 4
1,071 points

Mar 21, 2007 4:43 PM in response to Allan Jones

Thanks gents!

Right now, it's re-installing OS9. I hauled everything off the mobo earlier, gave it the once-over. I added RAM last week and will run the RAM check, and the battery is a week old. I think the initial culprit may be the original 8GB hard drive that the OS was on. It's dated from 1998, and sounds a whole bunch like not-quite grindy, hot rubbing metal. Like a dry bearing is inside. Very loud! Anyhow, the slave drive is a big 80 gig that I bought 16 months ago, so I partitioned it and am going to set that up.

Deb.
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User profile for user: Appaloosa mac man
Appaloosa mac man
User level: Level 5
4,330 points

Mar 21, 2007 5:11 PM in response to Deborah Terreson

Deb,

"so I tried the force re-boot keys (cmdcontrolpower), and I got a blank rectangle with the '>' symbol in the upper left corner. Never seen that one before. "

Not sure how you got there but that is the programmer's interupt for entering command line instructions. Older Macs had two buttons, one for reset and the second for the command line interrupt. All is well after a PRAM reset and boot from CD or external SCSI device.

Jim
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User profile for user: Allan Jones
Allan Jones
User level: Level 9
68,600 points

Mar 26, 2007 6:57 PM in response to Deborah Terreson

Sounds like they sold you hi-density RAM for a peecee. That's why the computer sees only half of it. A proper 256MB RAM module for the Beige G3 will has eight chips on each side. The ones I've ordered from Data Memory systems all work. I get the PC100 sticks for the B&W G3. They're the same price (sometimes cheaper) and will work if I get crazy and over-clock the old box.

A
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User profile for user: Deborah Terreson
Deborah Terreson Author
User level: Level 4
1,071 points

Mar 26, 2007 7:36 PM in response to Allan Jones

Yeah... I should have caught that. It's got the chips on one side only. I didn't bother to open the static bag at the store. I'm just so bent about dealing with this merchant - it's an authorized Mac dealer, so you'd figure that they'd be able to keep track of the difference in the stock - granted, it's old memory, but after getting two bad, old sticks in a row, you'd think that the last one would be the charm? Alas, not so.

Though on a cool note, my brother dropped by two nights ago - he managed to lay his hands on a Panther install set, and a cheapo no-name USB 2 card.. we installed the USB easily enough and got that up and running in OS9 (I love Tome Viewer) and was going to install OSX for him after I got the memory upgrade.

I was so P.O'd by what happened earlier, that I decided to just give it a whirl on installing OSX without taking any of the kit out.. I wasn't expecting it to work, but it went in as slick as anything, and I'm using it right now!

The thing I noticed with the Sonnet cards is that they can run without the cache enabler - I'd gone through this when I was having the video problems with the 1Ghz ZIF I bought last year, and fingered that if it worked then, that the install may take now. The USB card is something really, and I mean REALLY funky and the box it came in claimed universal operability on all platforms. They weren't kidding. The ATI card is a Radeon 7000 I ebayed for 20 bucks last summer and it's got native support from OS X, so that worked also!

All in all, this has been a pleasant surprise in an otherwise frustrating deal with the memory. I don't know what I'm going to do about the RAM though. I am loathe to pull it out, given that I do have OSX in now, but this system does need more memory.

Ermmm.

Deb.
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User profile for user: CEB II
CEB II
User level: Level 2
475 points

Mar 27, 2007 1:14 PM in response to Deborah Terreson

Deb,

I've found that sticking to RAM from Data Memory Systems (DMS) or OWC is a safe and economical practice. Their prices are fair and they seem to know what they are doing. They will also stand behind their sale until it works in your Mac. I've purchased numerous RAM chips from them for a Beige G3, Power Mac 6100, and HP LaserJet 5MP without any regrets.

Glad you isolated or at least overcame the system bus failure. Some of them can be transient problems like mine was on my Beige G3. My frustration with never completely eliminating the problem while using XPF and Panther on that machine ultimately caused me to retire the Beige and buy a used MDD G4 with Tiger.

Carl B.
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User profile for user: Eustace Mendis
Eustace Mendis
User level: Level 7
25,416 points

Mar 27, 2007 5:01 PM in response to Deborah Terreson

Deborah Terreson,

I think everyone who tinkers with their Macs has at sometime or another bought bad RAM. My worst experience was with OWC some years ago. (They not only mislabelled the RAM I bought, they insisted it was my fault that an alleged 222 was seen by my Mac as 322. I returned the RAM but I lost a few bucks on that - Canadian taxes and phone calls - and they lost a steady customer.) My best experiences have been with a company called RamDirect.

In any case, the moral is that we have to shop around, and be aware there are a lot of junk sellers out there.

Good luck.
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Bus Error At Startup

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