A1278 820-3115-B no USB

[hgoncalves]

Hi,
I have an A1278 820-3115-B, that works well, but that the USB ports doesn't work, and I don't know where to start.

Testing them with the Chipmunk USB Tester , on one port I don't have any activity (light). On the other one, it seams to have activity, but have no 5V light. The 5V power rails seams to be ok.

Can you help? Where should I start?

 

[2informaticos]

Realy strange, the USB tester requires 5V power to flash.
Test with a pendrive with Link LED.
Ports fail in both USB 2/3 mode?

Check L4605/705 and small coils in series with USB data lines.
U4650 can be easy bypassed, if needed.

 

[hgoncalves]

Hi,
I've tested them with a regular pen drive, but no activity (no blink light), and it fails with 2/3 modes.
L4605/705 seams to be ok, and the coils also.

 

[2informaticos]

Check diode mode to ground on all data lines.
Is better to compare with good board.