Red x in circle after replacing hard drive, logic board?

I don't think it has to do with being fully charged. It could be that the hard drive cable is not properly connected. On a classic that I replaced the battery on, I ran into the same problem. I tried several different logic boards but still had the same issue. I went back to the original logic board and it started working. The point is sometimes you just have to mess around with it for enough time to get to work. It still could be a faulty logic board though. If you have the original logic board (and it is still working), try that one. Make sure to get it working BEFORE you put the case back.

"Resolution

Restore iPod from Disk Mode

1. Disconnect iPod from your computer.

2. Manually put iPod into Disk Mode as explained in support document 93651.

3. Open the latest version of iTunes and connect iPod.

4. Restore iPod as explained in support document 60983.

Doc 60983

How to restore iPod

1. Ensure that you have an active Internet connection as new versions of iTunes and iPod Software may need to be downloaded to your computer.

2. Download and install the latest version of iTunes if you do not already have it installed.

3. Open iTunes, and then connect your iPod to your computer using the USB or FireWire cable that came with your iPod.

4. After a few moments, your iPod will appear in the Source panel in iTunes.

5. Select your iPod in the Source panel and you will see information about your iPod appear in the Summary tab of the main iTunes windows.

6. Click the Restore button. You will be prompted with one or more restore options that may prompt iTunes to automatically download the latest iPod Software. The 4 possible restore options are:

Restore Option 1: Restore - Restores with same iPod Software version already on iPod.

Restore Option 2: Use Same Version - Restores with same iPod Software version already on iPod even though a newer version is available.

Restore Option 3: Use Newest Version - Restores with the latest iPod Software available.

Restore Option 4: Restore and Update - Restores with the latest iPod Software available.

7. If you are using a Mac, a message will appear prompting you to enter an administrator’s name and password.

8. A progress bar will appear on the computer screen indicating that the first stage of the restore process has started. When this stage is completed, iTunes will present one of two messages on screen with instructions specific to the iPod model you are restoring.

Restore Instruction 1: Disconnect iPod and connect it to iPod Power Adapter (typically applies to older iPod models).

Restore Instruction 2: Leave iPod connected to computer to complete restore (typically applies newer iPod models).

9. During the stage 2 of the restore process, the iPod will show an Apple logo as well as a progress bar at the bottom of the display. It is critical that the iPod remains connected to the computer or iPod Power adapter during this stage. Note: The progress bar may be difficult to see since the backlight on the iPod display may be off.

10. After stage 2 of the restore process is complete and the iPod is connected to the computer, the iTunes Setup Assistant window will appear asking you to name your iPod and choose your syncing preferences similar to when you connected your iPod for the first time."

"I had the issue as well after replacing the hard drive, the hard drive cable, and the battery. Then played around w the hdd cable and now it works. Thank you and best of luck with this.

Patrick Carrington"

I did not see the further reading on here, And i wish I had because it would have helped me figure it out quicker, but yes, I eventually just tried a new HD ribbon cable due to lack of new things to try and that fixed mine too.