The answer? Yes the R10 was not compatible with the 5600G. Swapping CPUs solved the issue. 
I had placed a R10 in a different case (a pyramid) some time back and wrote briefly about it in the forum. Worked great. However, I decided to move it yet again to another case. Mostly the same everything except a few more fans which can be unplugged. The big difference is the processor, an AMD Ryzen 5600G. Note the G. The other difference is no Lunar Light although I am using the button off a dark Side Of The Moon case. Is that what it is called? The black R10 case. A 2,1 flash is written to be “system board failure”. I doubt the system board failed. Additionally, the head color is yellow or amber. SAME:  MB, RAM, PSU, FRONT PANEL, FRONT FAN, TOP FAN, EVGA COOLER, GPU AND HEAT SINKS - That all worked yesterday. 16GB RAM is in DIMM1.  Any ideas? Is it the G? I know the board cannot like make use of the G (on chip graphics) part. Thank you. 
Same R10 Computer, Different Case - Alien Head Blinking Two Then One.