2001 error after replacing backplate with flex cable's

Hi guys,

Im stuck with an annoying error on my iphone 5s. Because all the volume buttons where not working, and the dock connector was not working anymore i decided to buy a complete new backplate with al the flex cable's included. This way i would only have to take out the logic back and replace it in the new back cover right ;)

Problem now is that the phone won't boot up at all. It is stuck in a loop. Only apple logo shows up for a few secs and then restart. So i started disconnecting al the components try to sort out what the problem could be. So i have nothing connected to the logic board anymore except for the screen and the dock connector. I don't use a battery during testing. But still the phone won't boot normally. iTunes can't restore the phone as well. it keeps giving me error #2001.

Any suggestions on how to solve this problem?

Could this also be related to the dock connector?