iPhone 4S - Error 9 when restoring firmware

Hello

I have a problem with an iPhone 4S. It had some problems from the beginning when i bought it from ebay.

When I was flashing the firmware i had error 4013. I read on the internet that i should replace the USB Cable or the bottom flex cable (with charging port, microphone). After replacing the bottom flex cable I still had error 4013.

I cleaned the motherboard in an ultrasonic bathtub using Isoproppyl Alcohol. Things changed a little bit, now i have Error 9. It keeps putting the phone into the restore mode. Before cleaining it i looked at the motherboard under the microscope and it had no signs of water damage etc.

I have some repair skills with bga and soldering, so if there is a need to repair the motherboard, i would be greatful for any hints.

Here is the video on how it behaves when I am restoring the firmware.

http://www.youtube.com/watch?v=aaPT5Al9o...