OK, it definitely sounds like a fan issue, especially if you have to 'manually' start it spinning... Perhaps it is a combination between heat problem, lack of fan spinning problem and maybe a bios setting.

usually you have the motherboard, with the CPU the clips onto... then ontop of CPU is a thin layer of HeatGrease/Thermal Paste, which the HeatSink (Metal Fins) sticks to the cpu and also clipped into the motherboard to make a tight-fit. Then ontop of HeatSink is a Fan that either screws into the Metal Fins or clips onto it in some method. Make sure you plug the Fan cable into the correct spot on the motherboard to ensure correct voltage is given, but also, the fan has a 'spinning/rotation' sensor that gives information to the motherboard if it is working correctly or not.

Now, I can't find the manual online, perhaps another TZ guy will be able to help out with that, as well as checking the BIOS for correct fan settings.

Good luck!