XO Troubleshooting USB: Difference between revisions
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Revision as of 02:09, 15 June 2008
This is the portion of the XO Troubleshooting Guide for diagnosing problems with the USB interfaces of an XO laptop.
One of the USB ports doesn't work
This is typically due to broken connector or solder joint at the affected connector.
All of the USB ports receive power from a common switch, so if there is a problem with power it is likely due to the above reasons.
None of the USB ports work
Measure the +5V supply at the USB connector (or across C509 or C551). If it is not present, the USB power switch and current limiter, U56, may be broken. It may be bypassed by a 0 ohm resistor at R466 for testing purposes.
If the audio (speakers) is also non-functional, then the problem is the +5V supply on the motherboard.
Motherboard signal integrity
A full set of eye patterns is generated for testing the wiring of each USB port when running the Open Firmware hardware tests. See Hardware Self-Test.