[mcdermd]

So, I've had this B&W 350 shipped to me. It was working fine when it left but when it got to me, it won't quite boot. Both LEDs DS7 & 8 are on. It gets a Bong, I see the CPU request LED (DS9) flash a few times, but then it will not init the video on the primary PCI bus and it won't continue onto the secondary either (no USB init).

Things I've done:
- Reseat all cards, RAM, processor
- Stripped out everything except one stick of good RAM and the Rage 128
- Reset CUDA
- Reset Mainboard
- Test battery (it was good @ 3.6v)
- Replaced battery
(I've done most of those multiple times)

I cannot reset PRAM or boot to open firmware because it doesn't get to the point of initializing the USB ports.

All in all, I'm thinking the Rage 128 just picked an inopportune time to die. Does that sound plausible? Would a bad video card cause the symptom I'm seeing? Anyone have any more tips?

[reader50]

Try a different monitor. I'm thinking the monitor it worked ok on was not shipped with it. The new monitor may be trying to default to a resolution/refresh that the vid card does not support.

Also, try booting from a CD, with the HD disconnected. I don't know the exact startup sequence, but a problem on the ATA bus - like a crashed HD - might hang the bootup before it got to the USB system.

Note, "Post" (Power On Self Test - startup diagnostics) is not a common term in the Mac world. Most of our members will not have understood your thread title, and wondered why you were worried about posting to the forum with a B&W that is having a boot problem.

[mcdermd]

Okay, I'll keep that in mind.

An update:

-The video card is good. I slotted it into my dual 500 G4 and it works just fine.

-I plugged in a different HDD and it makes no difference.

-Tried three different monitors, no difference.

-Noted that at some point the secondary IDE cable had been pinched in the hinge resulting in one of the cable's wires being severed. Replaced the cable with no difference made.

-I can't really do much of anything beyond hardware as it won't get far enough along that it initializes the USB. As a result I can't use the keyboard. An interesting note is that the USB keyboard power switch will turn the machine on.

-it won't boot from CD with HDD disconnected

-Processor Heatsink warms up just fine (I think the proc is fine)

So, it sounds like the logic board is toasted to me. Too bad as it's a Rev B board and a new one will cost more than what I paid for the machine.

[reader50]

This PDF is the closest thing I've found to an Apple hardware reference manual for the B&W. It outlines the boot sequence, starting on the bottom of page 77.

Your severed IDE wire was likely grounded to the case when it was cut. This may have damaged one or more of the bridges - there is a motherboard block diagram on page 33. Alternatively, it may have damaged one of the power rails from the power supply. I was looking for a pinout of the motherboard power connector, so you could check voltages, but that document doesn't seem to have such a pinout.

[bowwowman]

Your severed IDE wire was likely grounded to the case when it was cut. This may have damaged one or more of the bridges[/B]

This could have also fried the ATA controller as well, which could have in turn lead to other failures.....too bad

[mcdermd]

Everybody is pointing to what I'm fearing: this logic board is toast because of that punched cable. Damn shame as another Rev B board is about as much as buying another entire machine.

Originally posted by reader50:
Alternatively, it may have damaged one of the power rails from the power supply. I was looking for a pinout of the motherboard power connector, so you could check voltages, but that document doesn't seem to have such a pinout.

But would the machine get as far as it is now if the PS was damaged?

Thanks to everyone that's threw in their two cents. It actually is appreciated a great deal!

How about one more question, this time about the Rev A boards. From my understanding the problem with them is you can only use one drive (the master) on the ATA channel otherwise you run the risk of corrupting the disks due to a less-than-perfect controller. Is there anything else? I mean, if I don't mind having only one HDD hooked up there, are there other drawbacks to using a Rev A logic board? I ask because I may have access to one for very cheap if I wait for a few days.

[Dr. Wahnsinn]

Originally posted by mcdermd:
How about one more question, this time about the Rev A boards. From my understanding the problem with them is you can only use one drive (the master) on the ATA channel otherwise you run the risk of corrupting the disks due to a less-than-perfect controller. Is there anything else? I mean, if I don't mind having only one HDD hooked up there, are there other drawbacks to using a Rev A logic board?

Rev A boards don't seem to like hard drives other than the ones that it Mac originally shipped with. Putting in a high capacity drive might lead to crashes and data corruption. Using an ATA controller card seems to take care of these problems.

[Detrius]

Originally posted by mcdermd:

But would the machine get as far as it is now if the PS was damaged?

No it would not. If you are getting a chime, your power supply is good.

BTW, if you get a chime, your machine did in fact POST. That's what the chime means.

This is straight from the service manual (which I do actually have access to):


Resetting the Logic Board

Resetting the logic board can resolve many system problems (see the Symptom/Cure tables for examples). Whenever you have a unit that fails to power up, you should follow this procedure before replacing any modules.

1. Unplug the computer.
2. Press the Power On button on the front of the unit.
3. Open the side access panel.
4. Remove the battery from the logic board.
5. Wait at least 10 minutes before replacing the battery.
6. Make sure the battery is installed in the correct +/- direction.
7. Reassemble the computer and test the unit.


The other thing you may not have checked out (but this is not likely what's going on):

4 Check jumper block configuration at J25. Make sure jumper block is correct color for processor type installed (see “Jumper Location J25” earlier in this chapter for more information). Also make sure the metal jumper pins are in the correct position in the block and the block is installed in the correct direction.

[Detrius]

Note also that I have had to replace logic boards before due to ATA cables that got sliced up in hinges.

[mcdermd]

Thanks for the notes, I've tried most of that, but I'll check over the list again.

What I did discover (and felt stupid afterwards) is that the hole in the IDE cable is supposed to be there. It's for the dead pin on an IDE connector.

So, back to the drawing board.

I did leave the battery out all night and still nothing. In frustration today, I cmpletely disassembled the entire machine and cleaned every last nook & cranny clear of dust and gave it a good polish too. Maybe that'll make it happy -

EDIT: More notes:
- LEDs DS1 (ATA) and DS6 (Ultra ATA) never light. I've checked the cables and drives. They work well in other machines.

- At boot I get DS7, DS8 (Power) and DS9 (CPU Request) all lighting up. Then DS9 goes out, I get the "Bong", DS9 flickers a couple of times, then nothing. I'm assuming that DS1(ATA), DS4 & DS5 (USB 1&2) and DS6 (Ultra ATA) should also be lighting as the boot sequence goes on, but they're not.

EDIT 2:
Addition to LED states: IF I set both drives to Cable Select and plug them into the first IDE connector, both DS1 (ATA) and DS6 (Ultra ATA) light solid for ~30 seconds then go out. Nothing else. This only works if I have it set to cable or slave and have them on the first IDE connector on the ribbon. Weird?

[tooki]

Originally posted by mcdermd:
What I did discover (and felt stupid afterwards) is that the hole in the IDE cable is supposed to be there. It's for the dead pin on an IDE connector.

Actually, that's not what the hole is for. The "dead pin" is the key to keep you from plugging the cable in wrong (not all IDE cables have the key molded into the plug). The hole is there for cable select mode, which blue and whites can't use, but the hole is part of the ATA-33 and higher standards.

tooki

[Detrius]

In your situation, the service manual points to the processor first and then the logic board. If you have another G3 handy, try switching out the processors. Don't forget the jumper blocks; make sure you get them oriented correctly; make sure you don't lose any of the jumpers inside.

[mcdermd]

Just an update for anyone that may reference this thread in the future. I ended up buying a used Rev 2 logic board for my B&W. I combined it with all the other parts from the old board. It did the trick and everything works well now. I think the problem with the old one was something in the PCI brigde that would not allow the ATA controller to come up anymore.

I'd like to thank the Low End Mac swap list for proving a great used parts marketplace.

Thanks for all the help in diagnosing this problem!