PS3 UPDATE LOOP

Hello, i have some problem, i got PS3 Slim from my friend like before 2 weeks, it was working fine, i tried to update it, then i got in loop, cant exit cant do anything, can i like install Custom FirmWare on flash and format HDD, then do the thing with turning on console(beep thing)? It wasnt Jailbroken before i think, so i thought if i can instant update it to Custom Firmware.
BluRay is problem, i opened console it was unattached. If i can do, can you please send download link like 4.91 NO...

PS3 UPDATE LOOP