Dell Studio 1425 "plugged In, Not Charging"

Tech Support Guy System Info Utility version 1.0.0.1
OS Version: Microsoft Windows 7 Home Premium , 64 bit
Processor: Intel(R) Core(TM) i3 CPU M 350 @ 2.27GHz, Intel64 Family 6 Model 37 Stepping 5
Processor Count: 4
RAM: 6004 Mb
Graphics Card: ATI Mobility Radeon HD 540v , 512 Mb
Hard Drives: C: Total - 461899 MB, Free - 373607 MB;
Motherboard: Dell Inc., 0VF0FR, A04, .6L454K1.CN7524108D0051.
Antivirus: avast! Antivirus, Updated and Enabled

Yesterday I had a Dell service onsite service technician come to my house to work on my computer. He replaced my palm rest, keyboard, touchpad and mousebuttons, and my WLAN card (had a V key missing, left mouse button was not working, and was having issues with high-bandwidth internet connectivity). Since he replaced these, my computer has stopped being able to charge. Unfortunately I did not notice this until after he left. My warranty expired August 23rd and I opened the previous warranty service before it expired.

So far I have flashed my bios, deleted and redownloaded the driver for the Microsoft ACPI-Compliant Control Method Battery in the Device Manager, shut off my computer without the battery and wiggled the charging jack to check whether it was a connection issue, and I have used an identical charger to the one I have. None of these have caused any change.