You may need to redo the thermal paste on the CPU and the graphics card. My g73jh needed a re-paste about every 3 months. The frame of the laptop wasn't strong enough to prevent the paste from de-laminating when I moved the laptop around.
So that's what the problem was! I had a g73 10 years ago and it burned through a graphics card and then ram while on warranty. It did get a bit better once I flashed a modded low power vbios i found on some sketchy online site.
Eventually it just stopped booting and I switched to a MBP.
