CTC DIY Printer problems

[Martin1656]

Hi, newbie here, can anyone help me, I have one of the above diy printers, and its never been able to print, first of all it said ready, but somehow the software i was using , Rapier host, also said it was printing but nothing ever worked, then i got an min temp, followed by an max temp error, so i cleared these, and the error came back, found an broken heater lead, changed the heater element, still got same error, swopped over the bed terminals to test the board connections and found it was the thermistor not recording temperature, i replaced the thermistor, and still the error was there, i contacted the seller, they sent a new board, but on fitting that, the same error came straight up, I tried a different board, an Anet manufactured one, of thesame design, but whilst the connections are exactly the same, the software isnt, and i could not get anything to work properly, so as i'm getting the same error, from a brand new board, any ideas , short of sending it back, ?