Issue while replacing my T14 Gen 2 screen with a UHD panel

Hey,

I’ve been trying to upgrade my FHD display to a UHD panel. I bought the required 40-pin eDP cable (FRU: 5C10Z23933) and UHD screen (FRU: 5D11C95781/CSOT MNE001EA1-5), which are the parts listed on the Lenovo Parts website.

I disabled the battery in BIOS and physically, then swapped the parts. Everything went fine until I tried to power the laptop back on for a test. It would not start at all, even with the charger plugged in. I initially thought I had damaged something on the motherboard, since I’ve read that this can happen during display swaps. I then reinstalled the original FHD screen and the laptop boots normally again.

Does anyone have an idea what might be causing this, or what I should check next? I'm wondering if I have a bad cable or if this broken. Would it cause this?