This answer by Michaeleangelo for similar problem but for V5-471, helped me to resolve. Just short two pins under G2101 (clear CMOS) to restart BIOS, you will find it on motherboard under RAM closer to laptop edge. If not helped then try to update your BIOS to your latest firmware BIOS firmwares official Acer support. Then I was able to invoke BIOS by pressing F2 at the start of laptop.