TaiChi x370 BOOT LOOP Dr.Debug 3E THEN 90

problem description
i believe i have 4.80 on the board for the bios but i can't fully post to verify. sticker is p2.20

it doesn't post it just powers on.. fans to max, dr bios led shows 3e and then 90. waits powered on for 30 seconds and reboots.

i have re-seated ram, video card, verified all psu cables are connected and solid. reseated m.2, pulled everything to just single ram (same behavior), a2 and b2 slots (same behavior), no ram (60 on led as expected), no video card doesn't seem to make any changes. nothing pugged into the back. (no usb or anything) no dice. it never continues past 90.

power supply is evga g3 1000watt.

problem started happening when usb keyboard (logitech g910) would lose rgb and just need to puggled in to come back. i did this last weekend, then i was finally able to get it to boot after waiting 30 minutes with cmos battery out for a full reset.   it did it to me again this morning, that is when the boot loop started. when i unplugged and replugged the usb keybard into one of the top usb's built into the motherboard the system hard froze. i rebooted .. then boot loop all morning. i have been unable to get it to fully post. it just continually boots, then 3e then 90.. 30 seconds later reboot.

any help would be appreciated. i received this as a christmas gift and installed it jan 28th 2018. i don't think i have the original receipt due to the gift nature. i believe i registered it shortly after. i do have the original box and accessories.

power off; turn off psu switch; pull the power cord out; press and hold the power button on the tower/case to dissipate any juice remaining in the capacitors; then press and hold the clear-cmos button on the rear; then plug it back in and turn on

I got a list of things to try from support. Nothing seems to work.

Removed motherboard from case, bench tested with another (known good) power supply. Attempted all prescribed and requested solutions to clear BIOS.   Nothing worked. Please see picture attached.   With out ram, would only boot to Dr Debug LED shows "60", place single ram into slot A. Then it would continue to do what was the original issue .. 3E then 90 on Dr Debug LED.

I can't seem to get this error to clear or have the BIOS cleared. So frustrating.

Please advise as to next steps.   I need to know if I can get this RMA'ed. Thanks for any help you can provide!!!

With Ram, nothing else



Without Ram, nothing else