4th Generation iPod not charging

When I plug it into the usb power brick

What happens when you connect it to the USB port on the computer? A 4th gen iPod should charge from a standard USB port. If it does not charge from any connection (but you continue to get that symbol), it may be a worn out battery.

NOTE: If this is a 3rd gen iPod, it only charges from a FireWire connection (not USB). 3rd gen iPod does not have a click wheel; it has touch wheel with four separate control buttons.

Be sure to try more than one USB docking cable, to rule out a faulty cable. I know that a 4th gen iPod (monochrome screen) starts up and connects with no battery (battery disconnected), when connected to USB. And it does the same with an unusably weak (but not completely dead) battery. But it's possible that a completely dead battery (one that won't charge at all) causes that battery symbol error. No way to knowing for sure, unless you replace the battery.

I made a mistake in my previous post. I think I was remembering the older 3rd gen iPod being able to start up without a battery connected. It does; just tried it with my spare "parts donor." But a 4th gen iPod does not. It just shows the battery symbol, if battery is not connected. It's not "the battery with exclamation point" that you describe, but it does not start up. When I connect an old (but still functional) battery, it does start up.

So, I think that makes it more likely that your problem is a completely dead battery. My guess is that a completely dead battery is like a disconnected battery, so your 4th gen iPod does not start up at all. When you connect your new battery, I think it will work again.

so the iPod boots up fine now, like normal... it does not charge whatsoever.

So, it sounds like the iPod now gets to its normal screen menu. What's your indication that that battery is not charging? Keep it connected for a hew hours. When you disconnect it from power, does the iPod stay ON or does it immediately shut OFF?

If the iPod is starting up properly when connected to power, it IS getting power, so I think the dock connection is working properly, at least for power. There are separate "pins" for the data connection.

Since you have several potentially faulty components, one suggestion I have is to buy a broken iPod of the same type on eBay or other online source. Buying a complete non-functional monochrome 4th gen iPod is often less expensive than finding a vendor selling the specific part (and those parts are usually used parts scavenged from broken iPods). Fortunately (for you), most broken iPods with a hard drive for storage are broken because of a bad hard drive. So, find one that is NOT described as having a bad dock connector or headphones jack, and chances are good that you'll have the parts you need. Plus, you'll have a bunch of other spare parts (like maybe the logic board and display). If the one you get is in better shape overall compared to your iPod, except it has a bad hard drive, you can even swap your working hard drive (and new battery) into it and use your iPod as the "parts donor" going forward.

I did this with 4th gen and earlier iPods about ten years ago. I wanted to see if I could swap parts and get some working iPods. Here are some tips.

- Avoid buying from a seller who looks a business. Often, that business is a buyer of used and broken devices, and those iPods have been scavenged already for working parts, so you might get an iPod that is assembled from bad parts. So that "Lot of 5 iPods" is often not such a good deal.

- Look for a seller who looks like an individual person trying to sell their own non-working iPod. These are more likely to be broken for a single reason, like a bad hard drive, and in decent shape overall. And you'll sometimes get extras, like a docking cable, power adapter, case, etc.

- There are two basic types of 4th gen iPods with monochrome screen. Thick and thin. The thick model has a higher capacity two-platter hard drive, and the metal half of the casing is larger to accommodate the larger hard drive. The front half of the iPod, connected to the plastic portion of the casing, is interchangeable between thick and thin 4th gen (monochrome screen) iPods.

- The color screen 4th gen iPod is significantly different on the inside (it's not just the screen). I don't have one, but I recall that even the connector between the logic board and headphone jack hold switch assembly is different. I believe the only internal parts you can swap between color and monochrome screen iPods are the battery and hard drive.

If you tried multiple docking cables and multiple USB connection points, the cause is likely to be on the iPod. The dock connector itself may be damaged or worn out, and not making contact on the pins used for charging.

What happens on the iPod's screen, when you connect it now? Previously you got the battery symbol with exclamation point.

I believe FireWire charging uses a different voltage, so you probably should not mess with the wiring. However, a 4th gen iPod CAN connect and charge using a FireWire port. Your PC is not likely to have a FireWire port, but some older charging accessories use FireWire charging. I have one like this

http://www.ebay.com/itm/Kensington-Stereo-Dock-500-for-iPod-w-Remote-/1419300431 08

It charges my 4th gen iPod (and 3rd gen iPod), and it uses FireWire charging because my newer devices (that only work with USB charging) do not charge from it. There's also the official Apple FireWire power adapter (and FireWire docking cable).

But it's not certain that FireWire charging will work. So you may want to go the route of finding a broken iPod that has a bad hard drive, that looks like it's in good shape otherwise. Swap your iPod's working hard drive into it, or use its logic board (with good dock connector) in your iPod.

Or just get your color screen 4th gen iPod fixed up (once you get that hard drive connector cable). Hopefully, it has fewer other problems...