Hey guys. I recently bought a second PS3 on the forums as i wanted a playstation for PSN and another for CFW etc. I was delighted to return my 80GB ps3 back to offical firmware , i deleted all created folders , removed all homebrew and deleted all my backups. On trying to acess PSN i was unable to due to error code 80710104. This is not due to a bad connection ( in my case , others may differ) it was due to the fact i had edited the CA27 file when attempting to use FCKPSN v0.6. After many attempts i have finally found a method to return PS3's from CFW back to OFW and able to acess PSN.
Tutorial - Ok , first off your going to want to delete all your homebrew and modified folders before we return back to OFW. this is a precaution however i do not know the effects if they are left on the system but its for the best.
next what your going to want to do is back up your PS3 to save all your gamesaves and game data , this will become clear in later steps.
Next your going to format your PS3 just to make sure everything is gone , and remeber to keep the back up from the previous step.
after that step is complete you're going to want to install your OFW. I jumped straight from REBUG 3.55.1 to OFW 3.61 , i dont know if it makes a difference but thats what i did and its worked so far. So to install the OFW you can either install straight from the XMB or the recovery menu. I choose the recovery menu so ill show this method. To acess the recovery mode
1. Turn off Playstation®3.
2. Hold The power button down; The system will turn on and turn off once again.
3. Once the System has been shutdown, re-press you finger until you hear 2 consecutive beeps
4. When you hear the 2 beeps take finger off power button.
5. You will be promted to plug in your controller via usb and then hit the PS button
6. The Recovery menu will pop up.
There's going to be six options , in this step your going to want to choose the bottom one , "System Update". pop your USB device with the offical firmware loaded on it into your ps3 , press select and start on your controller and install the firmware. Follow the steps and thats you returned to OFW.
If you attempt to sign into PSN you'll face an error message 80710104 stating they're is a DNS error. I presume this is from the modified files in the CFW you've installed but its not a problem.
Finally your going to want to go back into recovery mode. Follow the same steps as before but now your going to select the fifth option , "Restore PS3 system". This deletes everything and makes the PS3 act as if it was the first time it had been turned on. After you follow the on screen instructions the XMB will boot up. Click sign up for PSN and say you want to use an existing account. Enter your details and bam ! PSN has been restored. I have no idea why this is needed to get back onto PSN after reinstalling OFW but thats the method which worked for me. The last thing you've got to do is restore your PS3 data and thats you.
Hope this helps some guys out there really ticked off with that problem .