[Trac #1378] Single USB port (port 1-1) failure
Zarro Boogs per Child
bugtracker at laptop.org
Fri Apr 27 22:11:52 EDT 2007
#1378: Single USB port (port 1-1) failure
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Reporter: cjb | Owner: mlj
Type: defect | Status: new
Priority: normal | Milestone: Untriaged
Component: hardware | Resolution:
Keywords: |
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Changes (by wmb at firmworks.com):
* cc: Gary.Chiang at quantatw.com, Gary.Su at quantatw.com (added)
Comment:
This is a component/PCB/assembly problem.
One of my preB3 boards was exhibiting the problem too. I could make the
problem come and go by wiggling the USB A connector on the board.
I unsoldered the connect , in the process breaking two of the small pins,
and found that
a) Pins 1 and 4 (VCC and GND4) were not soldered to the board at all.
They were perhaps touching their pads, but the pins did not go through the
holes. No solder at all had flowed onto their PCB pads on the component
side of the board.
b) Looking at the pins and the through holes under a microscope, it
appears that the PCB holes are too small for reliable insertion of those
pins.
c) The build quality of the connector itself looks suspect. The rear of
the connector is a small captive PCB that ostensibly connects the contacts
inside the connector shell to the pins that mate with the PCB. Looking at
those mating pins under a microscope, it appeared that they were poorly
soldered to the small PCB. I verified this with an ohmmeter - one of the
pins did not have continuity to the PCB.
I soldered 4 short (2 cm) pieces of rework wire directly to the
connector's captive PCB, and thereby connected it to the XO PCB. Now that
port works quite reliably.
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Ticket URL: <http://dev.laptop.org/ticket/1378#comment:1>
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