As I said in the original post,  the bench supply is capable of more than 
3A...far more than the BBB takes.    I've duplicated the problem on 2 
difference bench supplies and with multiple BBBs (ie the problem is not 
specific to one particular BBB board).    

J-


On Friday, December 13, 2013 10:49:07 AM UTC-5, Kees k wrote:
>
> Hey, did you try another power supply? Probably the PS has problem 
> supplying the current and drops voltage? Or there is a current limitation. 
>
> I tried to reproduce by only connecting P9.5, P9.6 and P9.1 (GND) , but 
> could not.
>
> On Tuesday, November 19, 2013 2:00:55 AM UTC+1, James Littlefield wrote:
>>
>> New to BBB but experienced with embedded systems.
>>
>> I'm working on a project using the BBB.    Supplying +5V (up to 3A) 
>> directly to the pins on P9 from a quality bench supply.   I've found that 
>> briefly switching the +5V supply OFF and then back on can pretty reliably 
>> leave the BBB in an odd state characterized by...
>> a)  No LEDs on
>> b)  Very little current drawn from supply (10mA or less)
>> c)  +5 present on P9.5 and P9.6
>> d)  0.687V on P9.7 and P9.8 ( should be SYS_5V ). 
>> e) P9.9  = 3.57V
>> f)  P9.10 = 0V
>>
>> I've found that once the system is in this mode no amount of 
>> pressing/holding the momentary BBB pushbuttons will get the system working 
>> again.    Removing input power,  waiting 10 sec or so, then restoring power 
>> will get things working again.
>>
>> Has anyone else seen this?    It seems sort of like an issue with 
>> the TPS65217C chip but I've not found any reported errata on that part.
>>
>> Thanks
>> Jim
>>
>>
>>

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