I was installing 5.50 GEN-A onto my psp slim which currently had 5.00 M33-4. And on the screen it was installing 5.50 GEN-A or preety much look like an official firmware 5.50 install. When it got to like 86% the psp just shut down so I thought maybe its done. Well I try to turn it back on and the power light is green but the screen stays off. What did I do wrong?