Shattered screen, replaced, still not working

Hi,

My Nexus 5 had a close encounter with concrete, shattering the screen. Not only was the glass broken, there was no image at all, just a black screen. The phone however still works, it vibrates, the sound works, it connects to my computer, ...

No biggie, I thought, so I replaced the screen. To my disappointment the screen remained black after the replacement.

I've checked the most obvious things:

- The connectors are good

- No apparent damage to the motherboard

- Battery works fine (4,2V)

- Phone still boots, connects to PC

I've tried factory resetting via ADB, but since the developer mode is not active, I can't.

Could the charging port flex be the culprit? Since this connects the screen to the motherboard.

A broken replacement screen maybe? Although, the original shattered screen also has no image at all.

Reviewing my replacement screen, I saw it was for a D821, my phone is a D820. I've read online that this should be no problem?

Anyone had a similar problem or anyone that could share his thoughts on this?

Many thanks!

Ruben