Phone not charging, being recognized by PC. What components to test?

Phone took a power jolt from a cheap charger and now it won't charge. Also isn't being recognized by PC (USB device not recognized error). Thinking the USB components (L3 and L4) are probably to blame. Pretty sure coil is still good since battery connector on board is reading 0.9V. I assume it should be reading 3.7V, but at least it is reading something.

Can anybody confirm or point me in the right direction?

Thanks.