Bed Heating problems, Ender 5 plus

Hi Guys. Wondering if anyone can give me some ideas. I have an issue with the bed heating in that the board doesn’t appear to be reading signals from the thermistor. Ive determined that the thermistor is okay by swapping the hot end and bed thermistor inputs over at the board at which point the hot end read-out gives the correct temperature of the bed. So Im assuming there is an issue with the board! is that a common thing to happen? printer is about a year old and hasn’t had much use. Really just wanting to confirm its the board. Cheers people

Or the bed heater/ wiring.