Touch screen not working after dropping (even after replacement)

Hello, so recently I bought an iPhone X for really cheap second hand as it had a broken screen. The seller said the screen had a vertical line throught it (it did) and that the touch did not work after he dropped it once. I bought it, replaced the screen and the touch is still not working, even on the new screen. I tried reseating the digitizer cable a million times with no luck. I suspect this might be a logic board issue, and that is what I am most afraid of. Contemplating whether to replace the whole logic board (150€, lose TrueTone and battery health reporting, rendering the device worthless on the resale market) or maybe try fixing the motherboard somehow - I have no capacity for that, so I would need to take it to a repair shop.

Please enlighten me on whether this really is a logic board issue and God bless in advance.