Dell precision m4800 GPU not being detected

The GPU on my mobile workstation sometimes works and sometimes doesn't, I don't know the issue I have tried reseating the GPU and cleaning the mxm slot once it stopped working after a month or so the laptop had completely died out and then after some days I tried turning it on and it had powered on the GPU also worked but after a day it stopped working again does anyone have a solution? (Sorry for my bad English I'm not native)