If so, and you've already tried a replacement OEM adapter and power jack, that leaves the system board as the faulty part. You will need  a new mainboard.  
Hi. There is a strange issue. Under load my laptop loses a charging possibility for a second then continues to charge and then do the same in a loop. This is really annoying. What is the issue? Power adapter is new, less than 1 day using. The same issue was also with the old (original) one.[IMAGE]  
Losing charging under load