>
> As the beaglebone is only 3.3v tolerant, and the ADC pins have a max
> tolerance of 1.8v.


Should read: Most pins on the beaglebone are only 3.3v tolerant with the
exception of the ADC pins which are only 1.8v tolerant.

On Sun, Feb 5, 2017 at 7:30 PM, William Hermans <[email protected]> wrote:

> Micael,
>
> For good measure, you should be aware that pins that are connected to
> external hardware. Should be isolated if those pins, and hardware are
> powered up before the beaglebone. I would think that if the beaglebone it's
> self is powering these external circuits, and hardware. Then this would be
> less of a problem.
>
> Additionally, I've had more than one beaglebone come across my "desk" in
> the last 4 or so years. One in particular is possibly form the first batch
> sold to the public. e.g. ~4 years old. I have heard people saying that if
> you pull the power, while the board is running, that the processor can be
> damaged from this action. I'm not saying to is false, I am just saying that
> it would probably be a fairly rare issue. As I've been in a situation where
> I've had to do exactly that, many times. As far as corrupting the operating
> system. It is possible, as with any operating system. But again, it's a
> fairly rare situation. You're just as likely to corrupt the system by
> installing an application, updating the system, or flashing an new image to
> the eMMC.
>
> So there is one thing I have not seen you mention if you've attempted this
> or not. Sometimes, the board needs to have the reset button pressed, before
> it will power up again. I've run into this a few times myself, and like you
> I was nearly convinced the board was dead. No power lights coming on. even
> after completely disconnecting the input power several times. I also power
> my own personal beaglebones the same way you do. Via USB. Anyway, I'm not
> saying this will fix your problem. but it is worth looking into. If in
> doubt which button is reset, it probably would not hurt for you to just
> press both of the button to the right of the ethernet jack, with ethernet
> jack oriented at the top of the board.
>
> Anyway, if you care for a much better "analysis" of what happened, and how
> to avoid the same in the future. It would behoove you to tell us exactly
> how many pins you had connected to your external hardware. What kind of
> periphery, and how much current source/sink + voltage levels. As the
> beaglebone is only 3.3v tolerant, and the ADC pins have a max tolerance of
> 1.8v.
>
> On Sun, Feb 5, 2017 at 6:38 PM, William Hermans <[email protected]> wrote:
>
>> Or as Gerald already eluded to in his first post. Voltage levels on the
>> GPIO's, or other periphery was too high.
>>
>> On Sun, Feb 5, 2017 at 5:18 PM, Dennis Lee Bieber <[email protected]>
>> wrote:
>>
>>> On Sun, 5 Feb 2017 07:55:47 -0800 (PST),
>>> [email protected] declaimed the following:
>>>
>>> >It doesn't flashes, no light at all.. during operation it went down.
>>> The BeagleBoard doesn't show up any longer as a hard drive. I connect via
>>> the micro USB port, and that is the only power source for the board.
>>>
>>>         If the unit is driving any other hardware, I'd be concerned
>>> about the
>>> power supply... USB is normally only rated for 5V 500mA max (normally
>>> that
>>> 500mA is distributed among up to four sockets of a hub).
>>>
>>>         However... "during operation it went down" is too vague to really
>>> comment upon... Failure points could be the USB to PMIC, the PMIC itself,
>>> or something later. A short between almost anything could draw more power
>>> than the USB could provide.
>>>
>>>         Also, if that unit is running normal Linux (rather than a totally
>>> custom embedded application), then shutdown should NEVER be done by just
>>> pulling the power... Pulling power could lead to a corrupt file system
>>> (though a corrupt file system won't affect the power LED, and maybe not
>>> even the status LEDs.
>>> --
>>>         Wulfraed                 Dennis Lee Bieber         AF6VN
>>>     [email protected]    HTTP://wlfraed.home.netcom.com/
>>>
>>> --
>>> For more options, visit http://beagleboard.org/discuss
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>>
>>
>

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