Acer eg50-kb mb12253-03m..usb not works

[pippo_one]

Hello everyone, I hope someone can help me:

mainb eg50-kb mb12253-03m 48.4zk14.03m usb 2 ports don't work:

the tests I performed are these:
1- from the diagram I went back to the IC U6301, in input there are the + 5v. but there are no output
2- from foot 4 (ic 6301) i tried the continuity of the connection up to pin 86 of ic "ITE" is ok


Pls can anyone help me to solving the problem?
Thank you

[lapfix]

Re: Acer eg50-kb mb12253-03m..usb not works

What about U6301 pin 4 voltage : the enable signal !

[pippo_one]

Re: Acer eg50-kb mb12253-03m..usb not works

according to the tester no voltage ... but is it correct to have a voltage at pin4?
can I see it with the tester or with another instrument?

[lapfix]

Re: Acer eg50-kb mb12253-03m..usb not works

Pin 4 is active when low , change U6301

[pippo_one]

Re: Acer eg50-kb mb12253-03m..usb not works

Thank you very much
i change "U6301" now the usb port works