Unable to restore firmware

HI ,

I'm unable to restore my iphone 4s. I've tried everything, but I think theres something damaged. while it was turned on, the Screen turned black, after restart, there was just the "connect to iTunes" Picture. No possibility to reinstall Firmware (DFU all tested) (Error 14 or 27) I think it's a Hardware Problem. But can anybody tell me the chip in who was save the Firmware? Is it the main processor or an other chip?