We are just trying to debug the problem. This is a process of elimination so that we can narrow down the problem.
I have two BBB Rev A5A and I have never seen this problem. Admittedly, I boot these boards over NFS and I use SystemD. I also use this device to switch the power to the BBB on/off: http://www.hardkernel.com/main/products/prdt_info.php?g_code=G137361754360 <http://www.hardkernel.com/main/products/prdt_info.php?g_code=G137361754360> With the 5V adapter always on, this ODroid Smart Power does a clean power-on via an electronic switch. Regards, John > On Dec 2, 2015, at 6:48 PM, Jonathan Ross <[email protected]> wrote: > > Got it into broken state again. My notes were incorrect, I see 5V on the > power button, and 0V on the reset button. Holding down power button for 8 > seconds results in a blip on USR2, but no boot. > I'm thinking it's got to be cape-based, and I'm holding a pin high that > shouldn't be high until after boot. But I'm not using any of the EMMC pins or > boot pins (or any P8 pins for that matter). > > On Wednesday, December 2, 2015 at 3:31:17 PM UTC-8, Jonathan Ross wrote: > I didn't test the 8 second holddown of the power button but I doubt it would > help, and unfortunately it's not a reproducible issue. I'll have to wait for > it to happen again. > From my notes, I was seeing zero volts on power, 5V on reset. > The zero volts on power was very weird. From the KL16 I'm "toggling" my own > effective power button that is a transistor between the power pin on the > header and ground. The KL16 pin was not driven high (I checked), so I don't > think it was the transistor on the cape that was pulling pwr to ground on the > BBB. And the physical button wasn't pressed in. It was as if the pullup at > the PMIC wasn't active, yet the power LED was on. Is that possible? > Wish I hadn't pulled the 5V power to reset, then I could do more testing. > > On Wednesday, December 2, 2015 at 2:11:58 PM UTC-8, Gerald wrote: > I would start with your cape design and try and rule that out first. > > The reset is an input pin read by the processor, not actually a HW power > reset. If the SW is locked up, this could happen. > > If you hold the power button for a 8 seconds or more the board should power > cycle. > > When it is in this state, what do the voltages read? > > Gerald > > > On Wed, Dec 2, 2015 at 3:54 PM, Jonathan Ross <[email protected] <>> wrote: > Once in a blue moon one of my beaglebones will get into a state where it has > power (the power LED is lit), but it is not booted. Normally this would be > fine, just hit the power button to reset. But in this weird state the power > button does nothing. The reset button does nothing. > I checked the power and reset button pins on the header, the power was low, > the reset was high. > The only way to get the board out of this state was to pull the 5V power. > I'm using a KL16 on a cape to do a watchdog on the BB, and reboot it via > power and/or reset buttons on the header if the BB stops sending checkins > over uart. This has been working great, except for the rare case where the > board ends up in this state where the power and reset buttons are not > functioning. > Any ideas how the BB could get into this state, and if there's any other way > to force a reboot other than physically pulling the 5v power? > Thanks, > JR > > -- > For more options, visit http://beagleboard.org/discuss > <http://beagleboard.org/discuss> > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. > > > > -- > Gerald > > [email protected] <> > http://beagleboard.org/ <http://beagleboard.org/> > > -- > For more options, visit http://beagleboard.org/discuss > <http://beagleboard.org/discuss> > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
