Can taping a cooling fan to the outside of my desktop case help cool the computer down?
Added (1). It may sound dumb, but I don't dare to open the case yet.
Plus, I don't have any spare external cooling pads/devices I can add to the desktop case.
So until I get one, is it okay if I do just that?
My rig is not a external machine. The monitor and case and all the parts are mounted together in a display.
Lenovo Ideacentre AIO 700
It depends. If you've had your computer for a while, odds are you need to clean it. Processors and video cards generate a lot of heat, so they have this thing called a "heatsink" that collects all that heat and disperses it into thin metal fins. A fan blows air across these fins, pulling the heat off the metal and cooling the processor/video card down. If dust collects on the heatsinks, the dust will act as insulator, and that heat can't escape.
So… Look inside your computer case. If it's dusty, get a can of compressed air and thoroughly clean it out. If it's not, then plug it in and turn it on to make sure all the fans inside are turning. If they aren't, double-check their connections, and replace them if you need to.
If you go to almico dot com and download speed fan. It will tell you the temperatures of the components in the computer. Then you will have an idea if it is overheating. You should clean all the fans and dust from the computer at least once a year. Adding a fan won't help without air flow through the unit.
I wouldn't. You'd either block more air from going in or interfere with the existing cooling system. The fan on the computer is designed to push hot air out, not push cold air in. I'd invest in a better fan or better heat sinks if you are having overheating problems.