No Power, won't charge totally unresposive Reset Doesnt work

Hi guys, I have an iPhone 4 that turned off with around 60% charge left. It was updated to ios6 via wifi the day before it turned off, which seemed to take a really long time. After the update it worked perfectly for about 1/2 a day then powered off by itself and has been unresponsive since. It doesnt charge, isn't recognised by itunes unless i put it in DFU mode. once in DFU mode it wont restore usually with the error code 1601.

When left to charge it doesnt dissipate any heat at all.

I have tried the following:

Reset (holding the power and home buttons together)

holding the home button whilst plugging it into the computer

changing the battery

changing the dock connector

any help is appreciated