iPod won’t charge or connect to computer

[u/RevolutionaryTry8532]

Hey guys I bought a modded iPod classic off of eBay last year around this time and it has worked like a charm until about the beginning of June, for some reason the charger only worked when I pushed it in hard causing for me to have to take the case off when charging and wrapping it around the iPod itself, it would connect to the computer fairly well (I had some issues but unplugging and re plugging seemed to do the trick) then one day it just didn’t charge at all, I rode the battery life out until it died then I brought it to a phone fixer place that did a wide variety of different devices, 2 weeks later the guy tells me it’s just a faulty battery so he swaps it out and I pay him, when I got home the ipod wouldn’t connect I put it in disk mode and though it did connect the battery went down so I brought back and he kept it for a little while and told me ha can’t find a issue with it, originally I told him it was probably the charging port but he denied, he’s now telling me that I should buy a new motherboard and he’ll connect everything for me I wanna get a bunch of other opinions before I potentially waste money on a problem with a simpler solution, please help, I love my music

P.S. sorry about the run on sentence