Hp G4 1209-tx usb not working

[Romulo]

I need help on this HP g4 1209tx the problem all usb ports not working, when i plugged in the usb flash drive or usb mouse and keyboard it shows installing then it stops and show unidentified device.When i checked on the device manager UNKNOWN device.I already tried reinstall the os and update the bios but still the same issue. can anyone help on this please

[Romulo]

Re: Hp G4 1209-tx usb not working

anyone can help on this please

[mcplslg123]

Re: Hp G4 1209-tx usb not working

Have you checked 8 pin IC near usb ports?? Post schematic for more detailed advice. Is it HM55 or HM65 mobo?? Might be PCH bad also

[Romulo]

Re: Hp G4 1209-tx usb not working

i dont have schematic for this model. driver ic near usb ports have voltages.it has HM65.could it be this bad?

[mcplslg123]

Re: Hp G4 1209-tx usb not working

See if this schematic matches. Chances of HM65 going bad is probably high as usb ports are controlled by pch through some IC.

[Romulo]

Re: Hp G4 1209-tx usb not working

thanks for the schematics on U23 G547E2P81U ic driver pin2 and 3 and pin 678 have all 5v.but when connected to ohms red probe to ground and black to pins.pin 2 and 3 hav 0.049v while pin 678 have 0.578v

[Romulo]

Re: Hp G4 1209-tx usb not working

anyone please help on this please

[Levi]

Re: Hp G4 1209-tx usb not working

Romulo, check pin 4 of u23 if enable signal is present or not. this signal should be 3.3v which comes from the EC to enable 5v to be switched from the input pins to the output pins of all usb port power switch.

[Levi]

Re: Hp G4 1209-tx usb not working

can test by jumping 5v from pin 2 to pin 5 to confirm if it works? then we can rule out pch out of the equation

[mcplslg123]

Re: Hp G4 1209-tx usb not working

I think 5v is there on pin6/7 of that ic-so no need to jumper. What is important is whether you are getting 3.3v on pin4 as suggested by Levi

[mcplslg123]

Re: Hp G4 1209-tx usb not working

if 3.3v not present on pin4, track that pin on kbc. Might be something wrong with kbc.

[Romulo]

Re: Hp G4 1209-tx usb not working

thanks for the response Pin 4 no 3.3v , checked with continuity its connected to pin 97 of kbc

[Romulo]

Re: Hp G4 1209-tx usb not working

anyone please on this please

[mcplslg123]

Re: Hp G4 1209-tx usb not working

You can try replacing kbc or else pch dying .....