after much testing with different Firmware Versions i found a way to "unfreeze" my H3PB with the current Version 3.03 !
First i forced a installation of the last Firmware Version 3.03 from the gopro Website.
For a forced Update/Downgrade you put the UPDATE Folder with the Firmware on the SD Card.
Then insert the Card, the Akku and then USB Cable and wait for the red LED.
Then press and Hold Power/Mode and Shutter same time until the Cam Beeps.
If the current Firmware on the H3PB is 3.0 or 3.03 then the Update starts directly.
With Firmware 1.04 and 2.0 the cam goes in USB Mode. Wait a few seconds then press and hold the Power/mode Button and a second later pull out the USB cable.
The cam seems to make the beeps for power of, but then beeps a second time and goes in update. Release the Button, when the Update starts.
As the normal Update process makes two reboots and continuos the update automatic, we have to do the procedure 3 times.
So after the first update part the cam boots to the normal screen and freezes, then pull out the battery and start the process again.
Then after the second part the same procedure again and you see finally the Message "Update Complete".
Now the Misc Folder with the Information File is created and the Update Folder deleted on the SD Card!
When you are on Version 3.03 and the cam still freezes after boot, then pull out the battery and wait 5 seconds.
Then insert the battery and the USB Cable, wait for the red LED and turn the cam on.
It should start in USB Mode, if not do it again by pressing Power and shutter the same time.
So now, when the cam is in USB Mode. Wait a few seconds, then press and hold the Power Button and a second later pull out the USB.
With the first beep release the power Button.
My cam now comes with the setup menu and i can use the cam.
i make pictures and videos and connected my phone.
Still working everything.
Now the Test Power off, wait and then normal power on.
Cam is still working !!
Next test Power off, remove battery, wait, replace battery and power on
Cam is still working !!
I hope a long time !!
Maybe this way help somebody to "unfreeze" his cam too !!
-->> UPDATE 24h later
A Day Later the cam freezes after startup again. I can do the same procedure to unfreeze, but after about 10 seconds the cam now freezes again.
If i get a longer unfreeze time again, i will try a normal firmware reload as recommended by gopro.