I have a HP zbook laptop that cost me about 3500 euro's. Recently I changed some trivial settings in the BIOS. After I saved and reboot the laptop hung at the bios stage. There was no way to get back into the bios and the keyboard was blinking a code that I had to contact HP.

They had to replace the entire motherboard due to a corrupted BIOS. So it was caused by a bug? The repair cost were about 800 euro's..