Front panel unresponsive after being left idle for a few hours

  • Recently my KPA (unpowered head) has become unresponsive after sitting idle for a few hours. I don't know long the unit had been in this state before discovering this. Fortunately it has not happened at a gig or at band rehearsal yet, but it is slightly worrying.


    The unit was in browser-mode both times it has happened.


    The first time, a couple weeks ago, it looked as if the brightness of the display and LEDs had been turned down to just a slight glow. The UI responded from the front panel, but attempts to change things didn't have any effect. The remote OTOH looked normal, and I could use it to switch between profiles and toggle effects. The unit was processing audio, but it sounded as if CAB-processing had been globally disabled. Had to powercycle to bring the front-panel back to life and audio back to normal. Could powercycle with the knob, but turning off was the only reponse from knobs.


    Today the front panel has died. What seems like normal LCD-backlight is all there is, and no dials or buttons work. Can not even power off with the power/mode-switch. Like last time, the remote looks fine and is able to switch profiles and toggle effects. Audio sounds normal, including CAB-processing this time, at least for the limited set of profiles I've tested. Had to pull the plug to power-cycle.


    The software version is 8.2.2 28378

    It is a few years old (2015). Are there any batteries on circuit-boards inside that need replacing and could cause such behaviour? I have never experienced anything similar before. My unit is frequently on from early morning to late evening, idle for hours between uses as I find quite normal for a home-studio environment.


    I've noticed that there is a new release out and will probably load that ASAP as I've been hit by the volume-loss-bug for certain rigs in the previous version. The change-log doesn't mention anything relevant to the problem I describe here so I don't expect the upgrade to fix my issue.

    Edited 3 times, last by heldal ().

  • Funny you mention this, I just had something similar happen to me. I left the unit on for maybe 2 days though in my case, woke up one morning and found the screen lit but nothing on it except for a horizontal line. A quick reboot fixed it though.

  • In the last few days similar things keep happening if i leave the KPA on and unused for a few hours. Now the front-panel seems dead, except from LCD-backlight. No response from any buttons or switches including the chickenhead. Meanwhile the unit seems to work normally and can be controlled both from the remote and from rig-manager. The only way to bring the front-panel back to life is to pull the plug and reboot.


    I should add that the front panel now stops working even when there is no computer connected. I can OTOH connect and start rig-manager to control the KPA remotely as if nothing has happened.


    It takes some time for the problem to develop so I have not yet experienced it at gigs or rehearsal.


    Now running OS 8.6.6.32765 and RM 3.2.65.17265.

    Edited once, last by heldal ().

  • Hmmm.. if I leave me car running for two days it will probably overheat and run out of gas. I think only refrigerators are designed to remain on that long. :/


    The simple fix is to turn it off when not in use.

    Larry Mar @ Lonegun Studios. Neither one famous yet.

    Edited once, last by BayouTexan ().

  • Hmmm.. if I leave me car running for two days it will probably overheat and run out of gas. I think only refrigerators are designed to remain on that long. :/


    The simple fix is to turn it off when not in use.

    We are not talking days. A couple hours is enough. It has not yet happened while playing, but it has happened once while I had a 5min break from recording. Even days or weeks should not be a problem for this kind of equipment. Unlike your car the powergrid doesn't run out :)

  • And there it got stuck. I remains to be seen if it is for good.


    I had left the KPA on during dinner and when I returned the front panel was dead. I could connect and communicate with it from RM and from the remote. Powercycling did not bring it back up. It displays the progress while loading the OS, then stops with the screen displaying KEMPER PROFILER. Nothing more happens even after 10 or 15 minutes. I have tried do disconnect everything including the remote but that changes nothing. I have also tried the procedures for rig, MIDI and system-reset in case that could clear some corrupt info, but get nowhere.


    Any tips before contacting support?

  • While composing a ticket for support I left the KPA at the point where it stopped dring boot and after a while, 10-15 min I guess, I turn and see that the unit is UP! None of the resetting I tried seems to have worked. At least system defaults are there as my master volume is only connected to monitor-out the way I want it. I then power-cycled the unit with the front-switch and it booted normally.


    Strange. It remains to be seen if it can be trusted again.


    Now running a backup, then experiement a bit more.

  • Funny you mention this, I just had something similar happen to me. I left the unit on for maybe 2 days though in my case, woke up one morning and found the screen lit but nothing on it except for a horizontal line. A quick reboot fixed it though.


    We are not talking days. A couple hours is enough. It has not yet happened while playing, but it has happened once while I had a 5min break from recording. Even days or weeks should not be a problem for this kind of equipment. Unlike your car the powergrid doesn't run out :)

    If you look at quoted post above, I do believe it said "days". ;)

    Larry Mar @ Lonegun Studios. Neither one famous yet.

  • If you look at quoted post above, I do believe it said "days". ;)

    Ahhh .. didn't notice that. Not from me though ... My KPA is never left on over night, but is regularly on all day for practise and recording. However, its components are mostly bits and pieces also found in industrial computer-gear designed to operate 24/7/365.

  • Hmmm.. if I leave me car running for two days it will probably overheat and run out of gas. I think only refrigerators are designed to remain on that long. :/


    The simple fix is to turn it off when not in use.

    Ahh come on ;) Hardly fair. A piece of electronics is not comparable to a car. The problem, and what we all dread happening, is a freeze when we rely on an item. And if it can freeze after 12 hours, it can also freeze after 12 minutes. I could understand it if it was left on for a week or so. But a couple of days ought to be no issue at all in this day and age. My boss gx700 could certainly be lit up for days without issues.

    And in the end, the love you take is equal to the love you make.

  • Ahh come on ;) Hardly fair. A piece of electronics is not comparable to a car. The problem, and what we all dread happening, is a freeze when we rely on an item. And if it can freeze after 12 hours, it can also freeze after 12 minutes. I could understand it if it was left on for a week or so. But a couple of days ought to be no issue at all in this day and age. My boss gx700 could certainly be lit up for days without issues.

    With the way power companies push out crazy voltages and spikes during the day, I make sure to turn mine off when not it use for longer than 30 minutes. I always cringe when the lights begin to flicker and my profiler is on. =O


    My wife leaves her computer on all the time. The problem is, she is always asking me why its locked up the next morning and mine is working fine -- it's because I turn mine off when I sleep (except the ones making crypto). :P


    Seriously, see if it locks up on you if you start turning it off for the night. If yes, then contact Kemper Support.

    Larry Mar @ Lonegun Studios. Neither one famous yet.

  • With the way power companies push out crazy voltages and spikes during the day, I make sure to turn mine off when not it use for longer than 30 minutes. I always cringe when the lights begin to flicker and my profiler is on. =O


    My wife leaves her computer on all the time. The problem is, she is always asking me why its locked up the next morning and mine is working fine -- it's because I turn mine off when I sleep (except the ones making crypto). :P


    Seriously, see if it locks up on you if you start turning it off for the night. If yes, then contact Kemper Support.

    Did you even read the thread? I've already mentioned that my KPA never runs over night. However, it's built mostly from components also used in industrial gear built to run 24/7/365 so it should be expected to be able to run stable for long periods of time. Around here the voltage coming off the grid is very stable, and has been for decades. In the days before online connectivity and frequent updates I could have computer-gear running without UPS continuously for months, or even years only limited by the occasional planned or unplanned outage.

  • With the way power companies push out crazy voltages and spikes during the day, I make sure to turn mine off when not it use for longer than 30 minutes. I always cringe when the lights begin to flicker and my profiler is on. =O


    My wife leaves her computer on all the time. The problem is, she is always asking me why its locked up the next morning and mine is working fine -- it's because I turn mine off when I sleep (except the ones making crypto). :P


    Seriously, see if it locks up on you if you start turning it off for the night. If yes, then contact Kemper Support.

    I have no idea where the OP lives, but if it is in northern europe i highly doubt unstable voltages is the problem.

    And in the end, the love you take is equal to the love you make.

  • After running for a few hours with only audio in and out connected I hooked up the remote and deliberately let it run over night. Now, more than 12 hours later it is still running normally. Strange as it only yesterday didn't run for more than max 2 hours before the front-panel would give in, and that was without RM connected. The KPA-side of the USB-cable was plugged in, but with nothing connected at the other end that should not matter.

  • Hmmm.. if I leave me car running for two days it will probably overheat and run out of gas. I think only refrigerators are designed to remain on that long. :/


    The simple fix is to turn it off when not in use.

    That's not a solution or a reasonable comparison. I leave my PC on almost continuously and never find it sitting unresponsive. If it happened repeatedly that would be a software or hardware issue, not a user error.