cycling on startup

Hi I can't start my PC. The mobo is an Asus Z-97 Pro. I've had this computer since 2014. It's a big gaming PC. When I turn on its power, a light comes on, the Q code goes from 00 to 16, then it turns off and repeats that (seemingly endlessly?) so each cycle is only something like 3, 4 or 5...

I don't know whats going on. I tried Everything what i found on Internet. Even tried to change my CPU to other motherboard and Other cpu to my motherboard. Everything works but this motherboard doesn’t start with my CPU. Everything seems to work perfectly. But it is cycling through the q LED...

Hi This weekend, I changed my motherboard's CMOS battery. Since changing the battery the computer won't start at all (not even to BIOS) and the code in the motherboard settles on A2, and that's it. To try to solve it, I've reseated the RAM, and unplugged and replugged the SATA cables HDD...