Dell C1765nhw it has a paper jam and I can't fix it

You're either dealing with a bad sensor, paper dust, or a hidden jam. The first thing to do is check for a piece of paper stuck in the track somewhere, especially if you just pulled a jam out; but if that's not the case, you may have dust on the paper jam sensor; the easiest way to fix it is to get canned air and blow around all of the sensors in the paper pickup area. That said if you still have issues, you may need to locate the sensors and blow it there locally. That usually resolves the problem.

However, if the issue remains the sensors are likely bad; it's not a common failure on the newer Lexmarks but I have heard of it and seen it on the older ones where it was far more common. Yes, your "Dell" is essentially a rebranded Lexmark; for years, Dell had a contract with Xerox, Brother, and Lexmark and just stuck their logo on their machines; most of them seem to have been made by Lexmark (you can tell based on the drum/toner design; as an example, the Lexmark "MS/MX" rebadges use the same drums and toner carts, but likely have different programming to prevent use of the Lexmark part on the Dell printer, and vice versa; in addition, the imaging drum CAN BE swapped when chipless. For the rebadged color lasers, the clue is the toner; they either use eerily similar designs or cut and paste the Lexmark toner like Xerox does today, there's no in-between unless Dell brings a non-US model under the Lexmark label as a Dell with a different design; even still, there's ALWAYS a clue). With Lexmark, it's usually somewhere towards the bottom, but it could be Dell uses the CTD sensors as double duty if you do not see anything obvious; see this photo, the red box is where the CTD sensor is on most of these legacy Lexmark designs (the GO line and subsequently newer non-GO models are completely different):

Those sensors require nearly full disassembly to get to :-(. Pray it's dirty if they are the jam sensor!!!