Originally Posted by alqali
That's strange. I have tried the code on two AT&T models and nothing happens. Which model do you have and can you explain what you did step by step to get it to work. I just entered it in the phone's dial pad and nothing happens.
It works for me, international version.
Also just put it as shown into the dial pad.
Though you should be abe to see some of the diagnostic tools if you go through the HTC Guide App, IF you have it in your app drawer? Doesn't give ALL of the possible diagnostics but it gives a couple of it.