Our Legion 5 was damaged when closing the lid with an object on the keyboard. The display then had rainbow vertical lines so I replaced with an OE Lenovo display. Since I didn't need to access the bottom to change the display, I failed to disconnect the battery. I may have caused a short when unplugging the display cable, but when I did get it back together, the laptop would not turn on. I swapped the old display and same thing.

I then put the new display back and tried to find a short on the and MB, and I accidentally casued a spark and took out the CPU...rookie error. So new MB, and now the laptop starts up and charges the battery but I didn't have a display, black screen after even a few min. I noticed I didn't connect the display cable under the heatsink so I carefully did this with the battery unplugged. When back together I turned it on and I had a brief power light, and after a few seconds it shut off, and will not turn back on.

Could this be a bad display cable? Please advise, all input appreciated.