so you mean that it will spin the umd disc for only 7 seconds right? Is that when you try and play the game or just when you put it in?
Ps. Do you have full CFW or light CFW installed on your psp?
If its full cfw then make sure your iso driver is set to umd required. Check vsh menu.
If light cfw then make sure that you have umd plugins enabled under the vsh menu.
To get to the vsh menu press select but onvy if you have cfw.