LCD Display Not working

My MacBook Pro 13" Unibody Mid 2012 Model has a very unique problem.

Tried searching for the solution online but could not find it.

Almost an year back, one fine day my MacBook display just went off completely. I sent it to the Official Apple repair shop where they said that the display pin on logic board is faulty and that the entire logic board has to be replaced.

As it was very expensive to get it repaired from official store, I approached a local apple repair shop (unauthorized). He also said the same, but could not confirm the 100% since he did not have a similar LCD LVDS cable to check if it is LCD problem or logic board. Quoting Rs. 30000/- for logic board replacement, I set aside the option and also my MacBook pro.

Yesterday I took out my MacBook pro hoping (miracle) that the LCD will light up on its own. But it did not.

I connected it to the TV, external display was working fine. But once the restarted the MacBook, the even the TV display was not working. I opened the back cover, replaced RAM, tried all combinations ...but still no use.

Then I removed the LCD connection on logic board and started the MacBook with external display connected. Eureka, it worked. And then every time I restarted it worked perfectly.

So my inference from this is that

1. With LCD connected to logic board - On boot the LCD is detected and the display by default is transferred to the LCD and not TV. Hence what I assume is that the display point on logic board is fine. Only the LCD panel is corrupt.

2. With LCD disconnected from logic board - On boot the LCD display is checked, but since it is not detected, the display is transferred to TV.

Does this mean that the LCD or LVDS cable or both are the faulty part and not the logic board as suggested by both the repair shops (authorized and unauthorized).

Please help me find a solution for this.