C-Bus eDLT wall unit continuous reboot

Discussion in 'C-Bus Wired Hardware' started by tiferm, Jun 8, 2020.

  1. tiferm

    tiferm

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    Hi All. I am hoping someone can offer advice. I have a problem with a C-Bus eDLT wall unit, photo attached. It was working fine previously but now only allows one button press after which it immediately switches off and reboots. It displays the boot-up screen, and then the cycle repeats. I can switch on a light circuit for instance but before being able to switch same off again the unit is busy rebooting already. Anyone have any idea what can be causing this or where I should look first?

    Any help greatly appreciated! C-Bus eDLT.jpg
     
    tiferm, Jun 8, 2020
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  2. tiferm

    Ashley

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    Start by checking the cbus connections and voltage on the back of the switch. When you press a button the current requirements will go up as the backlight comes on. If there is a bad connection or low cbus voltage the unit voltage could drop low enough for it to reboot.
     
    Ashley, Jun 8, 2020
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  3. tiferm

    chromus

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    Is it constant reboot, or constant wake-up? I had a buggy unit that just would wake-up all the time,

    does it reboot with the "press a button to continue", or just light up?
     
    chromus, Jun 9, 2020
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  4. tiferm

    tiferm

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    Thanks Ashley I will definitely start off by checking the connections on the back of the switch and also the C-Bus voltage. Coincidentally it is one of the units furthest away from the power supplies, so I am hoping the distance is not the culprit causing a significant voltage drop. As mentioned it did work fine previously. Am I correct in saying the the voltage should be 36V DC ideally and absolute minimum 25V?
     
    tiferm, Jun 9, 2020
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  5. tiferm

    tiferm

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    Hi Chromus. I think it is a constant reboot. When the unit wakes up with proximity, as I approach to press a button, I manage to get one button press in, the specific light circuit is switched correctly and then immediately afterwards the unit goes dead and then appears to be booting up since the screen goes off and after a few seconds displays some writing which looks like a BIOS boot display. Can't recall the writing exactly and unfortunately the unit is not with me.
     
    tiferm, Jun 9, 2020
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  6. tiferm

    tiferm

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    Hi Ashley/Chromus. I had a look at the connections and voltage on the back of the switch and it seems fine. The voltage measured with a multimeter is 29V (also confirmed on the unit's display during boot up). Please see attached the boot display I was referring to. The C-Bus extends further from this connection in daisy chain configuration to another eDLT switch and that one is working fine which leads me to believe distance is not the problem. I am a bit puzzled why this unit drops out after button press/proximity wake-up and reboots repetitively. I've removed the unit and brought it home. Is there any diagnostics I can run with a USB connection without a C-Bus network since I don't have access to C-Bus where I live now? But I do have a C-Bus Toolkit installed on my PC. Or do you perhaps have any other suggestions? The installer advised the unit is out of warranty since it was installed in 2017 and warranty is only 2 years so I would really appreciated a solution other than replacement. Any help greatly appreciated! 20200610_131936.jpg
     
    tiferm, Jun 10, 2020
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  7. tiferm

    chromus

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    "2 years warranty" is loose, and in WA has no legal support, as a premium device with a premium price tag in WA we can expect far longer from warranty, I don't know the laws for other states, but I would certainly contact clipsal support about it and remind them you spent a LOT of cash on this gear and you expect better than 2 years in a domestic setting.
     
    chromus, Jun 11, 2020
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  8. tiferm

    Ashley

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    Chromus is correct here. The idea of a warranty has been replaced by Australian Consumer Law which now says a product has 'to be fit for service' and a domestic switch of this value should be expected to last much longer than 2 years. Manufacturers still try and hide behind warranty but it has little legal standing (Car manufacturers and dealers are particularly good at this :)). Push them a lot harder and remind them of their obligations.
     
    Ashley, Jun 11, 2020
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  9. tiferm

    tiferm

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    I fully agree with you both. For a premium product like this still in mint condition to fail so quickly is very disappointing and it is even more disappointing that it is not covered under warranty anymore. The caveat however is that I am based in South-Africa and therefore not protected by Australian Consumer Law. One would think our consumer protection act also applies though. I will definitely contact Clipsal locally and see if they can't accommodate. Thanks a lot for your help Chromus/Ashley!
     
    tiferm, Jun 11, 2020
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  10. tiferm

    chromus

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    If the local distributor is a pain, contact Adelaide and plead your case. If their distributor is doing bad things for their reputation they might want to help.
     
    chromus, Jun 11, 2020
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  11. tiferm

    Conformist

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    No need to plead your case. As Ashley has stated, you are covered by Australian Consumer Law (ACL). Schneider Electric(SE) can put whatever they like on the product documentation as far as warranty duration is concerned, but it cannot overrule ACL. The basic test is, how long do you think the product should last under normal conditions.. Components of a system like C-Bus are premium from a cost perspective and therefore should last at least 8-10 years. You'll notice more recent warranty statements from SE (in the last 3-4 years) include this detail about Australian Consumer Law.
     
    Conformist, Jun 11, 2020
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  12. tiferm

    tiferm

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    Thanks a lot for the input guys. I have contacted Schneider Electric and hope to hear back from them soon. Hopefully they can help without this becoming too much of a headache.

    In the meantime I investigated a bit more and connected the unit to a 29V DC power source to mimic the voltage measured where it is installed. I also connected it to my PC via USB and ran C-Bus toolkit. Seeing as the unit drops power I was hesitant to try a firmware update since a drop-out during firmware update is usually a sure way to make anything electronic unusable. Nevertheless I managed to get the unit stable on the standby display showing time and date by keeping a relative distance from the unit (so as not to activate the proximity sensor) as shown here:
    https://drive.google.com/file/d/1WSHwVJEbhwI05_1UhXTTjG7NeOXCAQF8/view?usp=sharing

    I then took the plunge and attempted a firmware update. Thank goodness it completed successfully and firmware was updated from 1.3.0 to 1.4.0. Unfortunately this did not solve the problem. As shown in this video where I approach the unit with my phone it seems the unit drops out upon proximity trigger: https://drive.google.com/file/d/1BDjp5bg2nIKT2UVm8uc8JfK-e6tLD-LN/view?usp=sharing

    Perhaps the problem lies with the proximity sensor causing the reboot?

    Either way the unit is definitely faulty and I hope SE can help. Once again thanks for everyone's advice!
     
    tiferm, Jun 11, 2020
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  13. tiferm

    chromus

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    Have u tried plugging it in at a different EDLT location on the network to see if the experience is repeated there?
     
    chromus, Jun 12, 2020
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  14. tiferm

    Conformist

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    Let me know if you have any issues and I'll help escalate to ensure it's sorted.
     
    Conformist, Jun 12, 2020
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  15. tiferm

    tiferm

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    When I did a firmware update as per my previous post I used a DC power supply, it was not on the C-Bus network and in a completely different location. Also, considering another EDLT further downstream on the C-bus, daisy chained with this one, works perfectly fine makes me think EDLT location is not the issue.
     
    tiferm, Jun 12, 2020
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  16. tiferm

    tiferm

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    Thanks Conformist, much appreciated! I don't want to be unreasonable so will give them some time to assist in resolving the matter. Will let you know if it leads no where.
     
    tiferm, Jun 12, 2020
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  17. tiferm

    JasonY00

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    I'm a little late into the game, but just a thought. Can you cover over the proximity sensor (perhaps with some black electricians tap) so it doesn't detect your presence? I don't know what technology is used. If you can, you may be able to rule the sensor in/out as the culprit.

    Also, can you set the brightness to a minimum on these things to minimize the power draw as it may be a thermal fault in the internal power regulation circuitry that manifests when only under load.

    These are only guesses as I don't have any of them, but it's worth a go. It doesn't sound like it will fix the problem, but it's always nice to find the cause...

    Cheers

    Jason
     
    JasonY00, Jun 27, 2020
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  18. tiferm

    tiferm

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    Hi Jason

    Just for an update first, Scheider Electric South-Africa was unable to replace the unit since it is going on 3 years and warranty is only 2 years. However, they were able to help me with a demo unit they had which is still in good working order so I commend them on finding a way to assist.

    With reference to your post, I think you might have hit the nail on the head. Previously I connected a 24Vdc and 5Vdc power supply with same current ratings in series to establish a 28.7Vdc supply similar to what the C-bus network voltage is at the premises where the system is installed. This is obviously just a DC supply with no C-bus network clock. The unit is rated to work with a minimum of 25Vdc and I believe C-bus is 15Vdc? So it is well within rated margins. The unit behaved exactly the same as on site with continuous reboots and occasional stints of stability. I also tried switching off proximity wake-up via the C-bus toolkit so the unit only wakes up from standby with button press. This did not solve the problem.

    Since my last post I tried one more thing which was to put another 5Vdc supply in series to up the total supply voltage to 33.7Vdc. This was before switching off the proximity sensor wake-up. With the increased dc supply the unit worked and was stable. However the odd thing is that it would not go into standby mode, as if the proximity sensor is permanently triggered. Which is ofcourse the reason why I tried switching of proximity wake-up.

    Finally tonight after reading your post I hooked up 33.7Vdc again and tried reducing screen brightness. The unit worked fine with 33.7Vdc and goes into standby correctly with button press as wake-up. All good. So the next step was to decrease screen brightness incrementally connecting 28.7Vdc after each iteration to check stability. Low and behold at 20% screen brightness the unit seems stable with 28.7Vdc and wake-up via button press works.

    So if I had to guess my hypothesis would probably be that the proximity sensor is malfunctioning and permanently leeching power. By increasing power supply or decreasing screen brightness this excessive power draw is compensated for and the unit works. From another thread on the forums it seems the technology used is capacitive proximity sensing so I don't know if black tape would work and not exactly sure where to stick it on the unit since no optic type sensor is visible. Perhaps best solution would be to disconnect the proximity sensor completely but easier said than done and will probably require fiddling on the PCB of the unit which is quite complex and components very small.

    Anyway since I have a working replacement it is probably not worth all the effort. But hey atleast it was a learning experience and hopefully it could be helpful to someone else out there.

    Thanks for showing interest Jason!
     
    tiferm, Jun 27, 2020
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  19. tiferm

    tiferm

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    Just when I thought I would let this one go I got curious and opened up the unit to see if there is any easy mod I can make to bypass the proximity sensor. Low and behold there is indeed a quick fix. When opening the unit you will notice the proximity sensor's contacts which press against the internal capacitive plate in the face of the unit. Following from Jason's idea with the black tape I thought it is worth a try to stick some tape on this plate where contact is made to render the proximity sensor open loop. Attached some photos for clarity. Unit closed again, screen brightness up to 100%, supply voltage at 28.7Vdc, standby wake-up with button press only and works perfectly just no proximity sensing.

    Now I have a spare unit with no proximity sensing which is not a major problem.

    Thanks for everyone's input on this thread!

    1 - Copy.jpg
    2 - Copy.jpg
    20200627_230121 - Copy.jpg
     
    tiferm, Jun 27, 2020
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  20. tiferm

    JasonY00

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    Wow, that's great news!

    I do love an opportunity to look inside such things to see what makes them tick. Perhaps sourcing a new proximity sensor may be interesting. They may be only a couple of dollars. However, it may not be the sensor but the support circuitry that is causing the problem. But worth a try if you are into tinkering.

    Just a side note, I understand that C-Bus is generally happy down to about 20V but this is pushing it and anywhere from about 24V+ is a better margin for reliable operation of the network. I have had old saturn switches working happily at 18.1V but don't recommend it.

    With this and your power transformer in the dud dimmer, you will be South Africa's go to person for C-Bus servicing!

    Cheers

    Jason
     
    JasonY00, Jun 28, 2020
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