Issues with black screening.

I am trying to trouble shoot a Lenovo yoga 2 11 (20332)

The machine appears to be shorting out through the power supply.

The machine hard locked and created a black screen with a red stripe- the machine would not charge and would not start with external power. This was resolved by opening the case and removal of the internal battery. The computer seems to run so long as the power cord is not moved in any way. If the power supply is moved at all the screen goes blank and then random shapes and collors tend to flicker accross the screen.

I suspect the AC harness has degraded or that there may be a Main Borad issue.

I would like any thoughts as to how to troubleshoot the issue.