Device won't turn on.

My HTC One M8 suddenly stopped working yesterday, one minute I was using it to browse the web with plenty of charge left in it (70%+) then 10 minutes later once I took it back out of my pocket it was dead, it hasn't been able to charge or turn on since then. I tried holding the power button and volume buttons for 2 mins and charging but that hasn't fixed the problem. When plugged in the battery shows up on the screen but just before it would normally go to the charging animation showing the battery charging up the screen goes back for a second and restarts the process, which loops until the charging cable is disconnected. The phone has recently (2-3 weeks ago) been repaired having a replacement USB/Headphone Jack board fitted (by a company and not me). The USB port seems fine from what I can tell and I haven't had any issues after the fix up until now.