Oh well, I'll use it later.

Mon problème

The touchscreen wasn't responding well. I bought a new display assembly to replace the old one.

Ma solution

Turned out the problem is probably with the digitizer connector on the logic board. There are a couple of little metal connections that seem to have broken, and the touch screen is consequently unresponsive in certain places. iPhone bricked. Oh well. I'll save the replacement display for when my wife's SE breaks.

Mon conseil

If your connector/port on your logic board is broken, a new screen won't help much.