ps2 backups

[csal5]

I purchased the neokey and the modchip for ps2 and neither of them work. I have experience soldering the chips but I have failed in completing the task and being able to play my ps2 backups. I have purchased back ups via internet of well known sites and they dont work on my ps2. I'm using the gameshark as the boot up disk but no success. Is there another modification that needs to be done to my ps2 or is it another swap trick.. Your help greatly appreciated. By the way I'm using nero as copy software.