Power Outage while playing... Kemper dead for a while...

  • Hi guys,


    Last Saturday we played a gig and had a short power cut in the middle of a song. The power resumed shortly thereafter but although all the equipment booted back alright my Kemper head stayed dead for about 15 minutes... unplugged, plugged back, tried different cables and outlets and I was starting to sweat seeing we could not finish the set... but when I was about to plug straight into the dxr10 with a OCD pedal to add some "grit" to the sound... I checked one more time and the KPA booted just fine...


    Any explanation as to what happened, and why did it take so long for the lunchbox to "revive" after the crash?.


    [Blocked Image: http://i.imgur.com/w5DVbGZ.jpg]


    A pic from the gig....

  • That's a regular "feature" of the KPA. Every time the KPS isn't shut down correctly it needs about 15 to 20 min to reboot. A lesson we all had to learn in the past. I never understand why this is needed - should be something to secure the proper operation of the linux OS used in the toaster. So it's not an error - it's a feature! Better prepare a drum-solo for the next gig to bridge the Kemper downtime :D

  • That's a regular "feature" of the KPA. Every time the KPS isn't shut down correctly it needs about 15 to 20 min to reboot.


    Not because it don't shutdown correctly, I had power outage during a gig , it immediately rebooted when power came back (20sec).


    As i remember, the Kemper needs like 15min to reboot (you have to let power cable unplugged) if something more "serious" than a simple power outage happens, like a power surge.


    A kind of security mode as you can have on some electronic stuff too.

  • Quote

    That's a regular "feature" of the KPA. Every time the KPS isn't shut down correctly it needs about 15 to 20 min to reboot. A lesson we all had to learn in the past. I never understand why this is needed - should be something to secure the proper operation of the linux OS used in the toaster. So it's not an error - it's a feature! Better prepare a drum-solo for the next gig to bridge the Kemper downtime :D


    I've had a few power cuts a gigs and as soon as the power is turned back on the kemper rebooted immediately. I've not heard of this 20 min waiting period ??



    Sent from my iPhone using Tapatalk

  • 15 to 20 minutes? There's definitively something wrong, I never had a power cut on stage, but I just did one and the KPA was completely rebooted after exactly 64 seconds.....



    And by the way: a tube-amp could be dead forever....

  • That's a regular "feature" of the KPA. Every time the KPS isn't shut down correctly it needs about 15 to 20 min to reboot. A lesson we all had to learn in the past. I never understand


    This is incorrect. Definitely not a regular "feature". I would contact Kemper Support and open a ticket....

  • That's a regular "feature" of the KPA.


    Not really ...
    Disconnecting power or switching the chicken head to "off" should do exactly the same thing. I thinkg CK also stated somewhere that he switches off his profiler by simply disconnecting power.

    MJT Strats / PRS Guitars / Many DIY Guitars -- Kemper Profiler Rack / Kemper Remote / InEar

  • I also remember that the KPA team said that this is something that has to do with capacitors still charged. If i remember correctly you can get rid of that long waiting time by simply unplugging the power cable turning the KPA on. This should discharge the capacitors. Then you should be able to plug the power chord back in and the KPA should power on instantly.


    I cannot confirm this but it might be worth a try. I think that the same procedure applies also to PC mainboards. It´s more a safety feature than a bug.

  • The procedure I described above definitely happens and was also subject of discussions in other threads. Try for yourself: Run your KPA and tear off the power supply cable, wait a little time and reconnect the cable. Now you're in the Bootup-Delay - qed!

    Feel free to do so, my KPA is running fine (except the bugs posted in other threads).

  • Disconnecting power or switching the chicken head to "off" should do exactly the same thing.


    Actually, this is not exactly the same thing. Powering it down will also close and unmount internal structures and stores a checkpoint.
    If you just cut the power, it won't find the checkpoint during bootup and will do a scan of these internal structures and recover them probably.


    Just to be clear: You won't loose anything when disconnecting the power, except a few seconds during bootup. There is never ever a data loss.

  • Thanks for your ideas guys,


    Definitely not a regular feature IMO, but the capacitors storing some charge that needs to go before rebooting makes good sense. In any event do you think that opening a support ticket is really necessary? I don't think so (and don't want to be a long time without my lunchbox).


    I'm shopping for a portable/cheapish UPS solution to prevent future problems like these anyways.


    Matt.

  • Hi guys,


    Yesterday I sent an enquiry to the Kemper Support Team to clarify this issue. This is what they told me:


    "Dear Mattlocked,


    There is nothing wrong with your Profiler. The internal power supply has a safety switch that prevents the unit from powering on for about 10-15 minutes after an accidental power cut to avoid any damage."



    So this is indeed normal and due to a security feature to prevent damage to the unit.


    Much relieved that my KPA is alright and will not have to ship it for repair.


  • This is interesting coz I have had 3-4 power cuts at gigs with my kemper and it has always come straight back on. If I had to wait 20 mins at a gig this would be a nightmare. I've seen people talk about UPS power supply's ???



    Sent from my iPhone using Tapatalk

  • Exactly what I said, you can also read about this "feature" in several other threads. If a KPA does not show this behaviour by an accidental power cut-off you should do a trouble-ticket to the KPA-team. ;)

  • Last Saturday we played a gig and had a short power cut in the middle of a song. The power resumed shortly thereafter but although all the equipment booted back alright my Kemper head stayed dead for about 15 minutes... unplugged, plugged back, tried different cables and outlets and I was starting to sweat seeing we could not finish the set... but when I was about to plug straight into the dxr10 with a OCD pedal to add some "grit" to the sound... I checked one more time and the KPA booted just fine...


    This scenario has nothing to do with data recovery. What you describe (device completely dead) happens, if the power supply protects itself against overcurrent. The power cut might have caused a power spike, which caused the protection switch in the Profiler to get activated. This switch will be released again as soon as the power supply is completely unloaded. Again ... the purpose is protection of the device. After a power cut on stage I once experienced that my 3rd party digital effects processor was dead and the built-in power supply had to get exchanged. I think, a power conditioner would avoid such issues.


    A data recovery with factory content plus about 30 performances takes a bit more than 2 minutes under current firmware.