Cellular Radio turned off, why can't I turn it on?

Hello, I have worked on several hundred phones over the past few years. I have done all kinds of brands, models, and hardware replacements, but I have a new problem that I just can’t seem to figure out. I did a lcd replacement on a Samsung s7 for a customer and all seemed well, until I saw that the radio off symbol was present.

I have tried to:

• Use the Testing Center to try ping test, as well as turn the radio on
• Replace the Antenna/Charge Port
• Use different sim, and no Sim
• Change APN Settings
• Turn Airplane mode off and on
• Factory Data Reset (data backed up)
• Visit AT&T Store to confirm settings on their end

After all of these failed, I bought a demo S7 from ebay, and knowing it to be IMEI incapable. I have tried swapping all of the parts between them, with no difference.

I then bought another MB and it also has failed. So, I am stumped. I would probably have been better off to just buy another s7 and swap them at this point. But, now I basically have 2 s7’s with identical issues, regardless of what parts I swap between them.

I am ready to move on, biting the bullet, and purchase a working phone to end my pain. But, I had to see if there is any hope for these two devices sitting on my desk…

Thoughts?