Question Sabertooth 990fx r2.0 motherboard

[MrCountry4747]

I have a Sabertooth 990fx r2.0 motherboard with AMD Fx 8350 With Kingston F3-1866C9Q-32GXM. If you guys ago the computer would not start with the start button I can’t get the computer started by pushing the MEMOK button on the board which gets me into the bios, the only way I can get it to boot into windows, is to select boot, and the drives for the operating system. I have checked the CMOS battery, which is fine I have change the memory settings. I purchased another sabertooth 990 FX motherboard and I’m having the same issues. can anyone please help me diagnose the problem and port me in the correct direction

 

[Misgar]

Have you checked the momentary action start button on the front panel with a multimeter set to continuity?

Have you tried bridging the 'Power On' pins on the motherboard header with the tip of a screwdriver instead of using the potentially faulty front panel start button?

If the start button and the MemOK button aren't working, how are you starting the PC?

Are both 990FX motherboards running with the same CPU and RAM (after swapping them over)?

What memory settings have you changed?

Have you tried the JEDEC standard speed of 1333 or 1066MT/s?