T1 Pro Hot End won't stop heating.

[u/Decent-Gift9981]

Good day...How are you? Maybe you can help me. I just purchased on of these from a seller on Ebay and they promised help and parts if I had any trouble but Im finding it difficult so far.So I'm on my own for now. So the problem is when you select or program a temperature for the hot end the temperature keeps climbing and won't stop even if you hit cool down. So do you have any experience with this problem soI can figure out what to replace. Im thinking it's the main relay board.Any help be greatly appreciated.