The problem was when I switch on the AC power to my laptop at the wrong time during bootup, the CPU is limited to 500Mhz. I have to do it in the right order - switch on power supply first, then switch on laptop.
The problem was when I switch on the AC power to my laptop at the wrong time during bootup, the CPU is limited to 500Mhz. I have to do it in the right order - switch on power supply first, then switch on laptop.