You should ideally be able to see the colour bands on the resistor and work out the value - but if the resistor is blackened or exploded and you can't see the colour bands then you have a problem.
A resistor might fail (rarely) by going open circuit in which case you could see the colours - but if it fails because of some trauma that mostly destroys it then it will be due to over current - too high a voltage across it - the symptom of some other component failing.
My guess is that if you replace R605 with another resistor of the correct value then that too will also fail.
Your challenge is to find out why R605 is defective
Good Luck..., March 2016
