After my dell Optiplex 760 is on for an hour or so, it starts ticking from the front fan over over the microprocessor. After it does that for a while it then will give a long tone that will not go away until a manual shutdown. What is this and how can I fix it?
Computers & Internet - Dell - Dimension - Dimension 4600 PC Desktop
Answers & Comments
My guess: your computer is over-heating, and the "tick-tick" is your notification that it is over-heating.
When it gets "too-hot", it automatically shuts-down, to prevent fatal damage.
Clean the dust from inside your computer, and ensure that the fans are spinning at their "full" speed.