(A copy of Ralph's email and attached photos follows. Note that generally the only source for Apple parts are authorized Apple dealers. I also checked www.pbparts.com and see they list the "Pismo Processor Heat Sink" assembly for $29 currently (plus shipping) on the 2nd page of their "Lombard/Pismo" parts listing. But you also shouldn't have to resort to buying another heatsink for a purchased CPU upgrade. See my note at the bottom of this page. -Mike)

Hello Mike, I really like your site very much. Great work! I often visit it to be up to date. Now I have some info, that could be useful to others.

I just was able to get a Pismo-cooler into my BlueChip G4/500 upgraded Lombard. Without it the Lombard tends to overheat. I was unable to do intensive tasks with it (with the original heatsink). The temperature reading of the chip is quite good. I compared it to the fan-turn-on-temperature with the old G3 Card and it matched. Additional I did measurements with a dual port digital thermometer. The junction temp of the processor was 10°C + relative to the top of the heatsink above the chip. I think these values also indicated a correct reading of the chip-temp.

Initially I had about 88°C to 92°C in idle mode. Rising very quickly to 105°C and beyond. Results were massive freezes of the system (OS X). (See below for screenshot of XLR8 control utility reading after the mod - 65C noted)

Then I tried to modify my heatsink and installed additional aluminium and copper plates to get more heat-imbalance. (see first photo below) In addition with ArctivSilver 3 Paste the idle temp was down to 72°C. With 100% load it went up to 88°C with the fan starting at 84°C. But the fan could not get this massive heat out of the case. So the temp could rise to 92°C over about 3-4 hours of 100% load operation. The fan was always running in this condition.

As I'm doing video tasks with intense calculations I didn't want to rely on this setup. So I wanted to try out a Pismo-cooler (Powerbook G3 2000 model heatsink/heatpipe assembly) and a Pismo-fan. I had to throw out the internal modem, because of the bigger heat sink. The heat sink plate was modified to fit correctly and in addition a hole was cut into the CPU case to fit the heatpipe.
All modifications were done in about 3 hours.
The result is very good. Idle temp is still 72°C (sometimes 68°C). But under 100% load the temp will only rise to 80°C. Then the fan comes on and after 10 min the temp goes down to 76°C. after 20 - 30 minutes the fan will switch off and comes on after 10 - 12 min cycling these states. With about 60% load the fan doesn't come on. The was not the case with my selfcontructed cooler.

The Pismo-fan is much quieter and has a higher airflow.
I've attached Pictures of my work.
Do you think additional information would be useful? Maybe I should give a detailed modification instruction with pictures?
Best regards
Ralph Radmacher

Photos:

Old Self-constructed Cooler

Pismo-Cooler and Fan in Lombard

Result for idle operation

(G4s don't provide accurate CPU temps as noted even by Motorola, but he noted a huge drop in relative temperatures after the mod - 68°C vs 88°C or higher.)

NOTE: I have to say that you should not have to engineer/buy another cooling solution for a purchased upgrade. There's been more than a few past problem reports in the CPU upgrade database here from past Bluechip owners, and today I've gotten two more Bluechip owner emails noting 6-7 months of delays waiting for a replacement module from a Bluechip LS/Lombard and a Bluechip Wallstreet owner. There is just no excuse for this kind of delay. I've been told that John Highhouse of Waypoint (powerlogix's distributor) is the best contact for those that have not received replacement Bluechip upgrades and I forwarded those mails to him. -Mike.

Other PowerBook Related Articles:
See the Systems page PowerBook section.