Relay turns on when computer is disconected

No change at all it does not reset the display does not blink it carries on as normal other that that relay clicking on. I just don't get it I've moved wires to make sure they are not picking up noise from he mains etc I'm stumped I've now rebuilt this 3 times same outcome every time i have even moved the pin from 9 to 8 to make sure it's not the channel. I do however seem to be getting 4.6v at the relay signal terminal but I'm unsure how sensitive the transistor is on the relay board and whether that is to low of a voltage triggering the relay.