Have a Toshiba qosmio that charge and turns on, but with no display and no cpu fan spinning. When powered on, cpu and gpu gets hot. Seems a missing voltage rail or a short somewhere.
Since its poweing on with the power switch, then 3.3v is available.
Any starting point to proceed with the diagnostic? ( checking coils, checking for short etc..).
Thanks in advance
It could be a lot of things. On some laptops fans do not spin until temperature reaches a certain degree. You need to manually probe for a short by measuring Capacitors and Mosfets in Diode mode. A thermal camera will help visualize thermal properties as the board is turning on and that can sometimes help narrow things down.
Thanks for your kind reply.
The cpu fan isn’t turning on at all, motherboard will shut down later when cpu and gpu gets hot.
When turned on, all the coils have voltages.. I will dig in more, testing mosfets and capacitors in diode mode and see what i can find.
Unfortunately, I don’t have a thermal camera. This should be on my purchase list later on.
Hello! Thanks for your kind replies.
Does this short cause the cpu fan not to spin? When turned on, cpu and onboard gpu gets hot. Will check for short around cpu and gpu.
On YouTube , i saw a video, same case but with an hp mb, turned out a shorted cap causing the issue. It was detected by voltage injection at the shorted area.
Thanks for your time !