Sandisk Flash-drive doesn't Show Up in Macbook Pro?

Hello friends,
I have recently bought a cool new Macbook Pro. I have 2GB Sandisk Cruzer flash drive. I have this problem from last wee. My Macbook Pro won't read Sandisk Cruzer flash drive anymore. One year before it is working fine and now it is not working properly. I don't know how to fix this problem. I don't know why Flash-drive doesn't Show Up in Macbook Pro? Please help me.
Thank you.

Try other USB ports if the light on the Cruzer flash drive does NOT illuminate when plugged in. If you still have the same problem then you have to contact your Sandisk shop from where you take this product and if you are in warranty, then take advantage of it. You have to replace it with another pen drive. If your pen drive is working properly in the another USB port then it means that your computer's one of the USB port has been damaged and you have to repair it.

Use following steps to fix this problem.
STEP 1 - Connect the Cruzer to the PC
If you receive a "USB Device Not Recognized" error on the computer, the flash drive is most likely failed. Additional troubleshooting is unlikely to correct the problem.
STEP 2 - Check under Device Manager
1. Right-click My Computer, and select Manage.
2. Click Device Manager on the left pane. If there is a yellow exclamation point (!) or question mark (?) beside the device, try to refresh the drivers.
STEP 3 - Refresh the drivers
1. Right-click on the entry with the error mark, select Uninstall.
2. On the top menu, click Action then select Scan for hardware changes.
STEP 4 - Verify if the flash drive is detected
1. Double-click My Computer.
2. Look for the Cruzer under devices with removable storage.

You have to use following steps to get rid out of this problem.
STEP 1 - Take note of all existing drive letters on your PC
1. Double-click My Computer.
2. List all drive letters that are being used or existing.

STEP 2 - Go to Disk Management
1. Right-click My Computer, select Manage.
2. Under Storage, click Disk Management on the left pane.
STEP 3 - Re-assign a new drive letter to the flash drive.
1. On the right pane, locate the corresponding drives of your Cruzer and U3.
2. Right-click and select Change Drive Letter and Paths on the drive letter associated to the Cruzer flash drive. (in the sample image, it's Disk 1)
3. Click Change.
4. Select a drive letter that is NOT on the list of existing drive letters under My Computer.
5. Click OK, and then click Yes.
STEP 3 - Change drive letter of the U3 system
1. Locate the box that says U3 System.
2. Right-click and select Change Drive Letter and Paths.
3. Click Change.
4. Select a drive letter that's BEFORE the drive letter assigned to the removable drive.
5. Click OK, then Yes.

MAC OS 9.0 and above does NOT require special drivers to detect USB flash drives. The USB flash drives will NOT be detected if the USB Mass Storage driver was modified or deleted. Remove all USB devices from the system, download the USB driver from Apple's website, then install it. Also try to plug the USB flash drive directly into the MAC computer, instead of plugging it to USB port on the keyboard.

I think your USB port lacks power and that's why you are getting such type of problem. If you have the device plugged into a USB hub or into your keyboard, plug it directly into one of the USB ports on the computer. If it works there, the issue is with the device to which it had been previously connected. The device may need more power than the port provides.

You have to check if the device is properly mounted or not. You can do this in following ways.
1. Open Hard Disk > Applications > Utilities > Disk Utility.
2. Highlight the name of your device, if it shows Mount on top, click Mount so that it changes to Unmount.

You have to check in the System Profiler. You can do this in following ways.
Open System Profiler from the Utilities folder, which is inside the Applications folder. From the Contents column on the left, under the Hardware header, select USB; the panel to the right will show all the USB devices that the computer recognizes. It may not identify them correctly by name, but it should have the right number of devices listed.
- If the device shows up in System Profiler, even if the device doesn't work, the issue is usually due to software. Your best solution is to try updating the drivers, creating a new user, or reinstalling the system software.
- If the device doesn't show up in System Profiler, the issue is more likely to be hardware—either the device or the USB port isn't working properly. In this event, continue on to the next item on this list. With each of the following items, check the System Profiler window (press Command-R to refresh the list) to see if the device appears.