@ Bokasa
Interesting that only your mouse port does not get the user5V on pin 7. My A4000T board has the problem where if it is slightly bent one way near the keyboard connector/F160 the user5V goes either low or completely from both the mouse and the keyboard and the whole computer stops working (slight bend the opposite way makes it work), unplugging keyboard usually fixes it. So different problem to mine but similar in that you have a problem with the user5v part of the circuit somewhere.
If you do not have the keyboard plugged in, does the mouse work? Just something to try that mostly works for me when my problem occurs.
@ Castellen
Good tips.
