I had a perfectly good working Pismo 400 until I sent the cpu off for an upgrade to Powerlogix for the 900 Mhz upgrade. I did everything they suggested but the powerbook won't start up. I just get one low tone, the hard spins up, and the green led flashes once every 4-6 seconds. What does the one low tone mean?

Brad (PowerbookMedic) has MUCH more experience diagnosing problems with processor upgrades than me, but I'd try two things if Powerlogix hasn't already suggested them:

1) Make sure you've seated the card correctly. You might have to push down a little harder than you expect to make sure the card is in.

2) Press and hold the PRAM reset button on the back of your Pismo for about 15 seconds. Then press the power button again.

You should email support@powerlogix.com. One low tone indicates a problem with your processor. A reset of the PRAM may help, but Powerlogix is the better source for troubleshooting.

-Bradley
POWERBOOKMEDIC.COM

Thanks for the tip. I tried both. The CPU definetly snaps into place. Pressing the reset button for 15 seconds and then trying to power up gave no change. I contnue to get one low tone, the drive spins, no chim or further start up, green led flashes periodically.

I've quadruple checked for bent pins using 10X magnification, unplugged the back up battery so the PRAM can reset, started the computer with option-apple-P-R with so change. Powerlogix thinks it is a problem with my memory chips not being fast enough to work with the new processor. I have ordered a PC133 memory chip whose timing is faster than the PC100 chips I currently have installed to see if the cures the problem.

Any other suggestions people my have are very welcome.

thanks.

It is possible it is the memory but prabably not extremely likely. Most likely it has something to do with the processor.

-Bradley
POWERBOOKMEDIC.COM

It turned out the problem was the memory chips were not fully seated in their sockets. Even though the hold down clip properly matched with the half moon holes on the side of the memory chips, it was possible for the chips to not be fully seated. I have recommended to powerlogix to improve their instructions in this area. A fairly high amount of force was needed to get the memory chips to snap into place. Not something I would expect to have to do.

Now that that problem is solved, the 900 Mhz upgrade works flawlessly.