At what temperature does an Apple III overheat?

[wowbobwow]

A quick Apple III question: does anyone know what the approximate internal temperature of an Apple III would be during one of its infamous "overheating" scenarios? It's widely accepted that early Apple III's would overheat after some period of usage, but I can't find any indication of just how hot they actually got inside.

If anyone has any knowlege or references on this topic, I'd be grateful!

 

[NeXT]

I'm speaking more from one of my slot machines (Bally converted Summit) where the compartment temperature (no ventilation) has been recorded as high as 41c during the summer and what caused the I/O controller to walk out of its socket was the thermal cycling caused by the machine being turned off at night. I'm sure an Apple III that was constantly left on would be less likely to have chips walk out.

 

[wowbobwow]

Full disclosure: the genesis of my question about internal temps is that I'm working on an article (and possible video) showing the temperature reduction achieved by installing some small cooling fans into my Apple III. I'm using some simple "DIY" fan-boards (powered by the Apple III expansion slots) and a Bluetooth temperature sensor to log some "passive cooling vs. active cooling" comparison data. My experiment isn't scientifically rigorous and isn't even *fair,* given that my Apple III is now equipped with a modern (and presumably cooler-running) Reactive Micro power supply... but I still think there's some interesting take-aways to be gained through the experiment. Knowing how close the "uncooled" Apple III gets to crash-inducing-temps would be a helpful factoid for my summary!

Bearing in mind the above, you've made a great point @NeXT - in the case of the Apple III, it was less about extreme temps, and more about parts that weren't suited to repeated cycles of low-to-high-to-low temps. I'll be sure to include that in my findings!

Huxley

 

[MicroCoreLabs]

I recently worked on a few Apple III's. You can google "World's Slowest Apple III" to read more, but I found that one reason that the system overheated was because some of the Apple IIC's get very hot due to running at 2 Mhz. I lifted a pin to force the machine to run at 1 Mhz full time which helped it run cooler and hopefully will extend its life.