Is your hold switch left on:

First things first, make sure your hold switch is not on .  This would have caused the device to ignore any inputs from the touch wheel.  If this is not the issue, continue below...

Dad battery:

If your iPod had been working recently, you may just have a drained battery.  Charge it using your computer or AC adapter.  Hopefully it will recognize the power input and charge.  If it charges, but you are not satisfied with the battery life, you should replace the old battery with a new battery.

Bad logic board:

It is possible that your iPod will not do anything when plugged into your computer.  The logic boards is likely your issue.  We stock the boards for 20 GB and 40 GB 4th Gen iPods, as well as the instructions for installing them.

Bad display:

You may actually have an operating iPod but not know it because the display is damaged/bad.  Make sure your iPod has a sufficient batter life and try to operate it normally.  After normal startup, hold the iPod up to your ear and listen for the whirring/humming of the hard drive spinning.  If the iPod sounds like it is working properly, but nothing is visible, it is possible the display is bad and must be replaced.

Bad headphones/speakers

Find another set of speakers or headphones to rule out your output device and confirm the problem is with the iPod .

Bad audio jack:

Distortion and a total lack of audio output can both be caused by a bad audio-out jack.  We offer free guides for replacement and can repair these onsite for you.

Corrupted software:

This can sometimes be fixed by performing a reset and restore.  You need to connect your iPod to your computer and visit iTunes to perform a restore.  Attention** this will erase everything on your iPod, so hopefully you have everything on the iPod already backed-up elsewhere.  Unfortunately, it can be necessary to perform this restore more than once to get your iPod working properly again.

If/When the restore does not solve your issue, you can perform a hard reset on your 4th Gen iPod by booting while holding the menu and select (center) buttons.  When you do this right, you will see a quick dark screen followed by the standard apple boot graphic.

Bad logic board:

When restoring the iPod didn't work, and you still have a sad iPod, it is probably caused by the logic board.  You will need to have it replaced.

Bad hard drive or cable

You may have a bad hard drive or a bad hard drive cable.  Listen to your hard drive when it is running to see if it sounds smooth and whirring normally.  Any grinding or clicking is a very bad sign for your hard drive and probably foretelling a total failure.  At some point, when the drive totally fails, you will not even hear the drive spin.  The cheaper course of action  is to start by replacing the hard drive cable, then if the problem persists, replace the hard drive.

Bad logic board

You probably need to replace the logic board.