Lid switch issue HP Pavilion G7

I had an issue with my monitor-picture was blinking and corrupted. I have disassembled it,cleaned the contacts and reassembled. Now the monitor switches on just in a narrow sector and switched off when fully opened. How to fix the lid switch or readjust it? Is it a magnet in the monitor bezel? Where can I get a close-up pic of the magnet to see if I misplaced anything when assembling the monitor?