Ipad 2 will not charge after update! Help

iPad 2 old software no longer can be updated it can only run on the last software working on

all you have to do here to upgrade:
https://support.apple.com/ios/update

Hey Janie,
We (Fixya) have no way to update ANYTHING... You must do this on your own, sorry..

Update the iOS software on your iPhone iPad and iPod touch

Yes!
Most people are now on iOS 8.4
So.... do you mean back grade? from 8 to 7
iOS 9 will be released in a few days!
https://www.apple.com/ios/

It can be downloaded & installed directly to your iPhone/iPad
Or... as I prefer.....
use my computer running iTunes to firstly Backup the iDevice (using it's USB charge cable)
ITUNES will at this time indicate that there is an update available for your iPad.
Choose to "download only" the new iOS.
If you have other things to do!
Disconnect while the download takes it's time downloading.
Then come back later and plug in USB cable and "Install" the updated iOS.
How to Update iOS Software on an iPad

Ipad 1 / 3g is limited to iOS 5.11 only. No idea if Ipad 2 can go up to iOS 8. Upgrading a older model with a newer software isn't really going to be smooth.

This article should have everything you need.
How to downgrade iOS 8 to iOS 7 1 2

- depends on the model of your iPad:
For the iPad first generation (A1219) to update is only possible with connecting the device to iTunes on a computer.
- but this model supports only iOS 5 - NO iOS 6/7/8
-------------------------------------------------------------
for all other models:
There are two ways to upgrade the iOS version of your iPhone, iPad, or iPod Touch - via connecting the device to iTunes on a computer
- or directly from within the device, but only since iOS 5, it is possible to upgrade the iOS version without the need to connect the iOS device to a computer (over-the-air update)
just go to: settings - general - software update

First Generation iPads can use iOS 5
- but iOS 6 / 7 / 8 need an iPad 2 or newer and are not compatibel with first gen. iPhone
-updates can be made in iTunes connected to a computer or under settings - general - software update
Upgrade iOS from within iOS device
(valid for iOS 5 and above)
Since iOS 5, it is possible to upgrade the iOS version without the need to connect the iOS device to a computer (over-the-air update). To upgrade to iOS 6/7/8, simply navigate to Settings > General > Software Update. The screenshot below demonstrates how to do so on an iPad, but this is also valid for the iPhone and iPod Touch.

in iTunes:
How to update to iOS 7

You can't get back the original OS.
Apple doesn't allow that.
Apple only allows (or forces) you to upgrade to the latest iOS version for your specific device.

i would suggest backing up your device to iTunes in your computer, the updating the iOS on your iPad
, or doing a factory reset where your iPad will be reset to the way it was when you got it ... though the iOS will probably be updated, then using iTunes to recover your files from your computer to your iPad.