[Trac #1378] Single USB port (port 1-1) failure

[Zarro Boogs per Child]

#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.

-- 
Ticket URL: <http://dev.laptop.org/ticket/1378#comment:1>
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