Installed gamegizmo 8 wire mod chip now playstation wll not recognize any disc's

[Big Chris]

As I say above installed 2 mod chips 1 in a 5000 model psx an 1 in a 9000 psx model start up the playstations both say the same thing "please insert Playstation CDROM" checked the connections over and over cannot find any problems.. asking anyone have you had the same problems with these chips from Gamegizmo. Is it the chips, or am I doing something wrong....