If your device does not power up, first check your device to see if the display is in tact and not completely broken since this could be the reason why the device seems to not be powering on. If the screen is intact, plug your device in to charge for a few minutes and then power it on. If it fails to power on then we can move on to inspect the battery. If the battery turns out to be the source of the problem, it must be removed and replaced. If attempting to repair the battery yourself, please reference the guide below to help you in your attempt to repair the device. Should you have any problems, please contact OnePlus directly so they can assist and help resolve your problem. OnePlus One Battery Replacement

To prevent any further damage to the usb port. Inspect the port in a well-lit environment. If the usb port looks to be damaged due to excessive force, it must be removed and replaced. If you attempt to replace the micro usb port, please reference the guide linked below to help you in removing and replacing this piece. Should you have an problems repairing the device, please contact OnePlus directly so they can assist you in repairing your device. OnePlus One Micro USB Port Replacement

For the OnePlus One smartphone, an OEM replacement part should be obtained directly from OnePlus. They can be contacted through http://oneplus.net/support.