iPhone 6 Short - KEEP Restarting

Hi Everyone, Hi @refectio Sir.

I have an iphone 6 ( its our personal phone , not water damage)

The phone simply drop down, and keep restarting.

Sometime, we can use it for some hours and then begin restarting.

I connect it to DCPS , phone absorb 0,08 amp (after ONLY battery connected)

The strange thing is, if i connect battery (i already try with new battery) the phone turn on automatically, without press power button.

If the battery is dead, the cable and battery logo appear continuously on the screen.

It seems, like someone press power button continuously.

i check all cap diode and filter connect with power button FPC but everythng is well.

Tristar , Tigris voltage is ok, phone charge normally.

I really dont understand how can i remove this short.

Thanks