Laptop won't POST with eGPU connected

[Aruj]

I have two laptops, Dell Inspiron 3542 (i3 4005u 8GB DDR3L) & Dell Latitude 3540 (i5 4210u 4+4GB DDR3L). The Internal displays of Both laptops are completely Broken. I used to use latitude 3540 as my main device, as it was much more powerful than the other. I also had a GTX 1060 6GB lying around, so i thought if i connect this to my latitude laptop, i would get a little better performance in games. (I know that there will be a huge CPU bottleneck but i did not have any other GPU) So, i bought PSU and a "Mini-Pcie to Pci express 16x riser" (A cheaper version of the infamous EXP GDC beast) and hooked it with my latitude. However, it did not work. I was not even getting backlit on my internal display. Similarly, no display on my external display (which i tried both connecting to my laptop and the GPU) . Then, i tried Turning off the Power supply (turning off the GPU), the laptop booted normally. So i enabled startup sound in windows to check if windows was even booting. However, I found out that windows was not booting as there was no sound and no light on the mouse. Then, I tried the hotswap method, I tried connecting the GPU after suspending the laptop (putting laptop to sleep) but nothing worked. Then i thought that maybe the Riser was faulty, so i connected it to my inspiron 3542. It worked perfectly on that laptop. It was even playing games without any issue. However, i wanted to game on my latitude which had a better CPU and dual channel RAM ( For getting less CPU bottleneck as my inspiron was having Hugee CPU bottleneck in almost every game) . So i installed a modded bios for my latitude laptop and started tweaking the BIOS settings. I tried everything in the video configuration tab, however nothing seemed to work, So I did the Rookie mistake #1, I disabled Integrated Graphics from the BIOS. Now i was neither getting Display with GPU connected nor getting display without GPU connected. Then i ordered CH431A programmer and SOIC8 to flash a new BIOS, however the modded bios was not getting flashed properly, so i found a working bios on the internet and flashed it. ( I returned the CH431A and SOIC8 )  The laptop was booting into windows (without GPU connected) , However i was not able to access the BIOS settings after flashing the BIOS, nor was i able to Switch to my external display (connected to the laptop) Until windows boots up. So, now my laptop is not POSTing with eGPU connected & a locked BIOS. Although I can still game on my inspiron laptop, However is there any way to make the GPU come to life on my latitude? Any help would be phenomenal.