Vertical bars on display?

Background:

I have a mid 2014 macbook pro 2.2Ghz and 16GB Ram and internal graphics card. Started having issues with restarts and crashes and hardware indicated on-board memory issue.

I bought a logic board that was 2.5ghz, 16GB with the discrete graphics. Installed logic board and everything was great.

I then found a great deal on a 2.8ghz board which in the end would have cost me much less after selling the 25ghz board so I said what the heck let’s upgrade even more. I installed the 2.8ghz board and there was no display. I said crap and figured I woukd just return.

I went to put the 2.5ghz board back in and now there are vertical bars (unlike I read about in other posts). I figured I had 1 of several things happen so I went to testing.

1) tested external monitor and it works fine (this leads me to believe the graphics card is fine)

2) tried replacing the lvds cable and no change.

At this point, i figured it must be the display itself. For some reason I neglected to try my original logic board for a few weeks. Once I tried it again, I discovered the display is fine (still had the crashing and on-board memory issue obviously).

So, I am trying to resolve the vertical bars from the 2.5ghz board. I have also tried every reset known to Apple like PRAM etc etc…

Here is what I have ruled out:

1) software/fitmware issue

2) display

3) lvds cable

4) graphics card

The only thing left I can think of is the actual lvds connector on the logicboard, but with the naked eye it looks okay. Anything I am missing? Any way to test the connector somehow or what to look for? Would cleaning connector help somehow?

Thanks in advance!!

Here is what the vertical bars look like.