the surface turns on for a while and then turns off, after I check the B+ voltage FROM CHARGER it drops gradually from 8.7- 0 V, I check the resistance at the 5V output inductor is about 11 ohms, normally in other brands of lapop the 5v block resistance is about 1 kilo ohm more, is it a 5v block on the surface output resistance is 11 ohms or is it a short indication?