IMO SMPS problem
There's a light on the MoBo which turns on when I turn the power button on. There are two front LEDs. AFAIK, One for Power (Yellow) and One For HDD (Red). Only yellow is turning up.
Then it either be a problem with GPU (or iGPU) or HDD.
SMPS, motherboard are having no problem.
^^ same problem was there few months back in my PC.. Mobo capacitors were gone kaput.. it might b the same issue in your case..
BIOS gives warning about high temps on CPU.
Since you are not getting display,either CPU or mobo is gone kaput.
^^ If it was a problem with HDD, the screen would have atleast showed something. Not a problen with HDD.
Something got to do with mobo. Because that beeper is not beeping. It is especially for the purpose of testing.
If MoBo shuts itself down due to high temp. How to does it turns on again when things are normal again? automatically?