Burnt out USB ports?

A few months ago, the fan on my power supply stopped working. Being lazy, I didn't replace it and intead used an external fan blowing out through the back. This seemed to work fine for a while, but yesterday, I left my computer for a few minutes and returned to find that my mouse and keyboard had stopped working. Also, there was a strange beeuzzing noise that happened 3 times, but only that first time. I rebooted, and the problem persisted. My desktop appeared normally, but no mouse or keyboard. I use an optical, corded USB mouse, which would receive power (ie. when plugged in, the red light on the mouse went on) but didn't move the cursor. My keyboard didn't function at all. I have 4 USB ports in the back, which are located directly on the motherboard, and 2 in the front which plug in. None of them work. Also, as of that day, when I start my computer, it takes much longer to load the BIOS and then even longer to load Windows (Takes About 3-4 min total to boot, instead of only 1 min. or so). The mouse works fine on other computers, I haven't gotten a chance to try out the keyboard. Anyway, I'm pretty sure that I fried the USB ports over the extended time (I'm not sure how long I used the computer with no fan at all, I noticed that the power supply fan had stopped working when computer games began to lag cyclically). I was wondering if this was definitely the problem, or if something else could have caused it, and if the USB ports are something I can replace, without replacing the motherboard. The computer is a DELL XPS 410 and is a little over 3 years old. I was buying a new computer anyway, and am now wondering if it is worth fixing or if I should just get another 2nd cheap desktop.

 

Greetings, general5678...

You can get PCI USB cards: here's Newegg's list...

If you can locate your Dell Service Tag, you can plug it in at the Dell Support page, maybe get a handle on what replacement parts you're looking at...of course, you'd want to go a little higher than recommended specs, and I'd buy any replacement parts at a local 'puter store or from an online outlet...

The fact that you're having multiple problems, however, leads me to believe that it may be cost ineffective to try to rebuild the Dell - sounds like you've got several different issues going on...