So my annoying 1520 again , Earlier was able to connect it to my lap via the usb cable , Now i tried to connect it ...... it doesnt really show that it is connected to the computer but its able to charge .
please help
If it's not the password/pin issue then it's likely related to a driver in your PC. There are a ton of 3rd party drivers that can screw with a computers ability to detect specific USB peripherals.
The old fun one that used to affect WP7 folks a lot was a PC driver designed to allow PS3 controllers to work on the PC. It would really screw up the detection for WP7 devices hooked into USB ports.