Mac-Mini falls into sleep while converting with ffmpegX

[tjm]

Hi all

Sometimes I record TV-Shows with a Formac Watchandgo-USB DVB-T Receiver. I liked it to convert them to DivX MP4 .avi-files. This worked for a while.

But suddenly my Mac-Mini began to fall into sleep while converting but this feature was disabled in the energy-savings panel. It is possible to wake it up by hitting any key and ffmpegX continues converting until it happens again.

I tried a lot. Changed the RAM and tested, installed a fresh system on an external FireWire-drive and tested, resetted the PMU and testet, resetted NVRAM and ALL by OpenFiirmware. Nothing made any difference.

Most important: If you do not wake it up, then it shuts down by itself after some minutes.

I monitored the temperature of the harddrive. It never exceeds 50 degree Celcius. The CPU load is quite heavy on conversion by aprrox. 100%. But seems to be normal.

By googling for "Mac Mini sleep issue" you will find that this issue isn't seldom and no solution to be found…

Does anyone know the issue as well or the cause and maybe a solution?

Kind Regards,
Tom

[jpschuck]

I had exactly the same issue a while ago on a Mini PPC 1,5 GHz. This problem went worse and worse until my Mac even became unable to convert any file because it went back to sleep immediately after waking up .

I also suspected RAM, hard drives, system updates, etc… Actually, it's really simple : this is just an overheating problem caused by the dust clogging the fan and the vents of the computer. As its components are all integrated in a tight space, the Mac Mini seems particularly exposed to this problem. FFmpegX is the first application to be impacted because it is very CPU intensive (almost 100% as you noticed) but if you don't do anything, this narcolepsy will occur with an increasing number of applications.

Open the Mac mini case and remove all the dust using a vacuum cleaner. You may need to unplug the DVD and hard drive during the cleaning process in order to have proper access to the fan. Don't forget to clean the vents on the bottom of the case (not only those in the back).

[tjm]

Thank you. Makes sense.

The Apple Service Manual tells this:

For reaching the fan it's enough to remove the complete internal frame at once. But you have to take care if you have a Bluetooth antenna or an Airport card installed. Beware of the cables. Furthermore you will have to remove the Capton tape that fixes the power button cable. First remove it, later refix it. The only tool you need is a #0 Philips screwdriver. Opening the top housing should be well known.

I will clean up my Mini after X-mas. Hopefully this will solve the problem. Nevertheless, cleaning the machine seems always be a good decision.

Kind Regards,
Tom