my usb points are not working

what exactly are you trying to do?

USB and Firewire information:

http://support.apple.com/kb/HT1151?viewlocale=en_US

USB:

http://support.apple.com/kb/HT4049?viewlocale=en_US

Firewire Port failure:

http://www.wiebetech.com/whitepapers/FireWirePortFailures.php

I would recommend Resetting the SMC and Resetting the PRAM as possible cures:

Resetting NVRAM / PRAM

1. Shut down your Mac.
2. Locate the following keys on the keyboard: Command (⌘), Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3. Turn on the computer.
4. Press and hold the Command-Option-P-R keys before the gray screen appears.
5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
6. Release the keys.

Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve

1. Shut down the computer.
2. Unplug the computer's power cord.
3. Wait fifteen seconds.
4. Attach the computer's power cord.
5. Wait five seconds, then press the power button to turn on the computer.