wilkes

I have GX270 power supplies, cpu fans and complete systems,I work on these all the time, usually it is the power supply ( made in china ) that makes the noise you are hearing.

better company to use

http://www.ascendtech.us/de...j1471.aspx

The power supply is fine. Unless the power supply is making the noise....

The fan is suppose to speed up when the processor is under a heavy use

More then likely you need to replace the CPU fan and heat shink and new thermal compound

http://www.discountelectron...amp;p=3299

Insides recently cleaned. That's not the problem. I think it needs pwr supply replaced. Who would you recomend for a reasonable price?

fans start at about $5.00, power supply's start at about $40.00 .
i would clean the fan first if that didn't fix the problem, i would replace the fan.
or buy a refurbished pc from http://www.walmart.com/brow...amp;depts= or an off lease pc from dell

Dell GX270 Optiplex. The fan speed fluctuates. Some times it gets so fast it sounds like it's going to fly off the desk. What is causing this? I've been told it could be the power supply. I've had the unit about 5 yr,s and it has fluctuated since day 1 but it is getting worse.