C350 -reboot while printing and jam?

[Toxic]

I have a problem with this machine like a title said.
When machine start to print/copy/or paper passage from service menu,first sheet of paper jams in half way out of fusing and machine reboot and report mishandled paper.
Sometimes it work good about 10 sheets of paper then jamed again.
I try to change clutch on paper transport unit,same thing.
Also i try to clean all sensors in transport drive section.
Few times a notice that paper is curle around transport roller,i dont know how.
Now i start to think there is a problem with power supply board or something like that because i never see that machine reboot when paper jam.
Tomorrow i will try to change complete transfer section from another machine but any suggestion will be great.

edit:forget to mention,machine does not show any jam in service mode counter except rebooting log.

[Toxic]

One more thing...
Machine jams always when number of copies is set to 3 sheet or more,never on 1 or 2 number of copies and it does not matter is it from tray1,tray2 or bypass.

[Toxic]

Complete transport section (cleaning pad,transfer roller,etc) change from another machine and same problem again.

[Stirton.M]

might be a failure of the MCB.

Swapping boards would be this step since you eliminated the transport section.