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Avnet Employee (Regular Contributor)
Posts: 44
Registered: ‎08-01-2012

Re: LX9 MicroBoard - Known Issues

Modifying the board that way should be ok from an electrical standpoint, but it shouldn't be related to the issue you are seeing and I doubt it would fix it.  The TPS65708 will operate on an input voltage as low as 3.6V so there should be no issue with the voltage drop across the diode.  Could the issue be related to the power profile on your USB port on your computer?  Based on what you described it sounds to me more like it isn't getting enough current unless both ports are connected.  It shouldn't be related to the input voltage but I would double check to see that your USB ports are capable of providing enough current on their own.  A good example is the USB expansion port on my USB keyboard, I can't connect peripherals to it that need power because it can't provide enough current.

Thanks

Chris 

BT
Visitor
Posts: 1
Registered: ‎07-10-2013

Re: LX9 MicroBoard - Known Issues

I'm still a little confused regarding the Micro-B pin mixup problem. Some of the posts imply that this is only an issue when using the LX9 with cell-phone charger style cables. Others imply it doesn't work with the cable that comes with the product. I seem to find myself in the second category. No blue or green lights unless I short pins 4 and 5 on J3 or plug in P1. Even then I can't get the Self-Diagnostics/Demo to run. I've tried two boards and two cables all with the same result. Does this sound like a cable problem or something else?

Avnet Employee (Star Contributor)
Posts: 582
Registered: ‎04-20-2009

Re: LX9 MicroBoard - Known Issues

This issue was fixed on Rev C, which was released in August 2012. If you have a Rev B, and you shorted pins 4 and 5, then it sounds like you have a different problem.

Bryan