I'm having this problem and it's driving me crazy 'cos I can't for the life of me work out why it is doing this. My CPU fan for the past 2 years has sat nicely at around 900RPM which is nice and silent. However, I recently modded my PC with a new case and some cold cathodes and LED fans. Now, everytime I turn more than 1 cathode on, the CPU cooler starts going crazy and speeding up and slowing down and it's quite annoying and then it settles down if I turn them back off. What can be creating this issue?
P.S: PC Specs if they help are:
CPU: Intel Core 2 Duo E6850 3GHz cooled by standard LGA775 third-party fan cooler.
RAM: 3GB Dual Channel DDR-667
PSU: Bestec 350Watt
Motherboard: Asus P5Q
Graphics: ATI Radeon 3650 HD
Others: 1 sound reactive cold cathode, 1 liquid effect cathode, 2 LED cathodes and 3 LED fan. Case also has 3 front backlit LCD Screens.
May seem overkill with the specs for this problem but I guess the more you know the better.
EDIT: Narrowed it down to it only happening when the liquid cathode is switched on. It doesn't matter if the others are on or off. Note it is not due to a temperature rise as the problem happens immediately and then stops immediately when turned off.
Maybe the current draw for the liquid one is too much for the psu to cope with,
is the liquid one on its own powerline? try having that on its own line and other bits on other lines, if its still freaking out, I'd say go shopping for a bigger psu