Downgrade progskeet 4.11 to 3.55 slim green led blinking

Hello,
I want to downgrade my ps3 slim with date code9c, version software 4.11, i dump with progskeet + winskeet 5 times,
i patch file (manual, auto with winskeet, flowrebuilder 4.2.2.0), and write on ps3, verify ok,
i have on screen: connect cable..., i put ps3 in service mode(dongle in left side, usb stick in right side),
and second part i open again ps3 and stay about 30 second and blinkind led green. In usb i put Lv2diag.self from Jaicrab + PS3UPDAT.PUP (355checkoff).
If exit to service mode i have same on screen: conect cable...

In JaiCraB_LOG.TXT, i have this :

Update BD firmware
read BD firmware package (1966992 bytes) elapsed = 147 msec
update BD firmware elapsed = 11 msec
Update BD firmware done(0x8002f147)
update package elapsed time = 84880 msec
Updating or Verifying failure 0x8002f147
UpMng.UpdatePackage() failure
manufacturing updating FAILURE(0x8002f147)
Total Elapsed time = 96662 msec


My dump is upload to this link: http://www.mirrorcreator.com/files/1...ump4.bin_links
and dump+patch: http://www.mirrorcreator.com/files/T...1.05.bin_links

If anyone can help me with a suggestion, thank-you very much.