How do I enter programming mode on HTC one m8 ?

[inewhandi]

How do I enter programming mode on HTC one m8 ?

 

[B. Diddy]

Welcome to Android Central! Are you talking about Developer Options, or something else?

 

[cytherian]

Welcome to Android Central! Are you talking about Developer Options, or something else?

I think he means diagnostic mode. *#*#3424#*#*

Incidentally, on a similar note, I have a problem with entering diagnostic mode. The code (above) works, but it takes anywhere from 2 to 5 minutes for my M8 to enter it. Conversely my previous phone (an HTC Evo 3D) took less than 15 seconds! I don't understand what could be causing such a lengthy delay.