stuck before boot, no screen, led on, caps and num ok, fan spinsWhether on battery with or without power adapter plugged in, or on AC without battery inserted the same behaviour happens:...
"Toshiba C850 won't charge when plugged by an AC adapter."に関する回答Check battery health, could be signs of an old battery not holding a charge properly. If the battery is not end of life then you should look at the power adapter and the first two mosfets.
"My laptop is not turning on"に関する回答have you checked the power adapter is working as it should ?
"black screen when I turn on my laptop"に関する回答similar issue here. on powering up the laptop the power led and wifi led turns on, the fan may or may not spin, the optical drive spins once and the num lock led turns on then off but the screen stays black. removing the battery, unplugging the power adapter and pressing the power button for a few seconds then plugging it again is sometimes enough to have the laptop turn on and boot normally. I’m about to open it and see if there’s any obvious issue inside and do a cleanup / change of thermal paste while I’m at it. hopefully this will help. -edit- I cleaned up the accumulation of dust, changed the thermal paste but the symptoms persist. I ran a test without optical drive and hard derive, plugging th laptop and powering it, the CPU and GPU instantly warm up but the fan does not start spinning causing the laptop to get quite hot. I used the multimeter to check the 19v power rail and it is present at different points, so probably not a mosfet issue here. I’m unsure the issue is screen related I suspect...