loud fan

hey guys i have a 6 years old powerbook .
Mac OS X 10.4.11
1GHz
512 MB SDRAM

lately the fan of the computer sounds so loud even when the computer in standby mood, and it would go quite only when i close the screen
any idea why is that happening? and what can i do about it?

many thanks

Have you tried looking at Activity Monitor? See if there are any applications running that are taking up a lot of your CPU. I've heard of people having "ghost" apps running in the background that they never knew where there which hog CPU.

At 6 yrs old it's entirely possible the fan(s) have just worn out.

But verify you don't have a runaway process. Would get the iStat widget if you havn't already. It will show you what's using the processor if that's the case. I had a runaway process yesterday morning using 70-90% of both processors. While Activity Monitor gave me the current CPU useage accurately, it gave no indication what process it was while iStat showed me the process right at the top of the list.

Oh, and FYI: the process I had ended up being syslogd and was pushing the fans to 6K. It was due to Time Machine. Had taken the MBP to another room, so I had the backup drive disconnected. The syslogd process was in a runaway mode. Even stopping it did not help. It just started up again almost immediately. Finally figured out to turn Time Machine off and that took care of it.