Digitizer doesnt work - Apple iPod touch

The Apple iPod is a handy device for listening to your favorite music, but mechanical issues can lead to frustration.

In particular, one problem you may encounter is a touch screen that ceases to function, whether completely or only on certain portions of the screen.

In some cases, a simple fix can solve the problem, while in others, a malfunctioning touch screen may be the sign of a more serious issue.Moisture

Moisture on your fingertips can cause an iPod touch screen to function erratically or not at all. Foreign substances such as hand lotion can also impact the touch screen.
A good practice is to thoroughly wash and dry your hands before using the device.
Wiping the screen with a microfiber polishing cloth can remove any debris accumulated on the touch screen, allowing for the direct fingertip contact necessary for proper functioning.
Barriers

Using a plastic sheet to cover the touch screen provides protection against dirt and smudges. However, the plastic can also create a barrier that prevents essential fingertip contact, especially if it is old and dirty.

Removing the plastic allows you to test the screen to see if it is hindering operation.
Wearing gloves when using your iPod may also inhibit the necessary screen contact, so removing them may also provide a remedy.

Ending Application If your iPod's touch screen freezes or becomes unresponsive when using a specific application, simply restarting the application may solve the problem.

First shut down the application; if this doesn't work, shut down the unit completely and then restart it.
Dead Spots
Instead of a completely unresponsive screen, you may experience difficulty only in specific areas. These "dead spots" are often the result of malfunctioning pixels, which are the components that comprise a digital image.

If you suspect bad pixels are causing your touch screen issues, notify Apple Support for repairs or even replacement.

According to the Tuaw website, Apple's policy has generally been to provide automatic replacement for iPods experiencing pixel problems.