Question Troubleshooting random reboots on my laptop

Sep 20, 2019

I need some help, about a week ago i started having problems with my GPU. I have a laptop lenovo ideapad 700: i7 6700 @ 2.6GHz, 16 GB RAM ddr4, SSD, GeForce GTX 950M. 3.5 years old

So, I was playing (iRacing) and suddenly the pc just rebooted, in a blink, never happened before. I got back and it happened again and again. then i started thinking something is happening. initially i though it was some overheat issues but I didnt fell the PC too warm. still I let it rest, I opened and cleaned the fans assembled it again and tested. the reboots continue.

Then I start reading in forums and on internet how to test things, I downloaded CPID HWmonitor, CPU-zZ, GPU-Z, memtest (for the pc RAM), memtestG80 (gpu RAM), VMT, furmark OCCT. In summary, i run stress tests on cpu, and gpu, individually and together. CPU was running well at 100% reached 70-5 C. GPU was not overheating (50-60 C) but reboots were happening during furmark, occt and memtestG80 tests, but no apparent errors appears in the logs. I had two alternatives in mind, either is a problem in the GPU ram, or the power supply was failing. I bough a new power supply with higher power, the old one was 130W, i orderd a 170W just in case. btw also tested removing the battery, no change.

the new adapter arrived today. I run all the tests again, and there were no reboots. in any of the tests. but when got back to play. i started geting reboots again. I also teste while playing other video games and got reboots.

any idea of how to know what is it that is failing? right now everything looks good, but im getting reboots.