XO Troubleshooting USB: Difference between revisions
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This is typically due to broken connector or solder joint at the affected connector. |
This is typically due to broken connector or solder joint at the affected connector. |
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All of the USB ports receive power from a common switch, so if there is a problem with power it is likely due to |
All of the USB ports receive power from a common switch, so if there is a problem with power it is likely due to a broken connector or solder joint at the connector. |
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The USB signals run directly from the connectors to the CS5336 Southbridge. If there is a [[XO_Troubleshooting_USB#Motherboard_signal_integrity|signal integrity problem]], and it is not at the connector, the motherboard must be replaced. |
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:There is no repair for this motherboard |
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==None of the USB ports work== |
==None of the USB ports work== |
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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. |
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. |
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If the audio (speakers) is also non-functional, |
If the audio (speakers) is also non-functional, that verifies that the problem is the +5V supply on the motherboard. |
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==Motherboard signal integrity== |
==Motherboard signal integrity== |
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The [[XO_Self_Test|hardware self-test]] provided by [[Open Firmware]] contain a section where test signals for the USB ports are output, allowing signal integrity (eye diagrams) to be made using an oscilloscope. |
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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|Hardware Self-Test]]. |
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[[Category: Repair]] |
[[Category: Repair]] |
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[[Category: |
[[Category: Hardware]] |
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[[Category: USB]] |
[[Category: USB]] |
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Revision as of 05:07, 27 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 a broken connector or solder joint at the connector.
The USB signals run directly from the connectors to the CS5336 Southbridge. If there is a signal integrity problem, and it is not at the connector, the motherboard must be replaced.
- There is no repair for this motherboard
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, that verifies that the problem is the +5V supply on the motherboard.
Motherboard signal integrity
The hardware self-test provided by Open Firmware contain a section where test signals for the USB ports are output, allowing signal integrity (eye diagrams) to be made using an oscilloscope.