Videocard broken?

I’ve got a Librem 13 V3 with the latest kernel 4.7-Purism-4. The OS is Qubes OS 4 RC5.

While surfing the internet the laptop made a huge pop noise and turned it self off. Now if I want to boot the laptop it turns itself off as soon it wants to go into the GUI mode. I’ve tried to boot the laptop with a live CD PureOS 8, but even with the live CD the laptop powers itself off.

At the time I had the laptop on my lap without the power plug, plugged in.

What else can I try to get the laptop working again?