After IOS7 update can not charge cellphone but shows device is.

I work at a cellphone repair shop and have a issue i can't figure out for the life of me. a customer of minds has a iphone 4s updated to ios7 and the device now doesn't charge. To be more specific, the device SAYS it's charging but the battery life continues to discharge. i've used the jewelry cleaner with 92% alcohol, and took another step of using a soft brush tip on all transistors, resistors, and capacitors. I even cleaned (brushed) underneath all the shields that are removable on the logic board. the device STILL shows a lighting bolt saying the device is charging but it is still discharging the battery while saying different. Has anyone seen this problem and fixed it? also willing to take any advice.