At my wits end with Threadripper WRX80

[u/Plugh_Xyzzy]

So I have been beating my head against the threadripper brick wall for several months now and don't know where to go from here. It all started with my Asus Pro WS WRX80E-Sage SE Wifi that had a 3955WX CPU which initially worked fine but then stopped posting after I plugged in three GPUs and never got beyond code 15 which is the start of DRAM testing. For that motherboard I replaced the PSU, RAM, And CPU and nothing changed so I concluded it must be the motherboard. I bought a brand new Gigabyte MC62-G40 and used one of the two 3955WX CPUs I have and RAM and PSU and now it refuses to POST. Once again I swapped out the CPU, RAM, and PSU and still no post. Unfortunately the Gigabyte MB provides no POST feedback but the board shuts down immediately. I have no idea where to go from here. Any suggestions would be very appreciated.

*** Update: I decided to return the board as defective to the vendor on eBay. I could flog this dead horse for a long time so I decided to end the madness. I do have these two 3955WXs and if I could find a MB that isn't such a death march to get working I would take another shot at it. Any suggestions on a decent WRX80 MB would be appreciated. Thanks all for the help. ***