Well first we need to get into service mode (which ppl are having problems doing)
after we get into factory mode then we have to plug in a usb in the usb slot closest to the disc drive thats in FAT format with only two files, Lv2diag.self FILE 1 and Modified 3.41 PUP and power off
Power back on and your ps3 should install 3.41 and turn itself off
so turn it back on and make sure its on fw 3.41 (also it should be in factory mode)
take out the usb and put in the Lv2diag.self FILE 2 and take out the previous files and restart your ps3 and you should be in 3.41
the files can be downloaded from here.
http://hotfile.com/dl/86801332/bfa5384/dgf.rar.html
but look this is not a comprehensive guide but all the key steps are here if you can get into factory mode then have a search on like ps3hax or psx scene