BEME ERod motor drive unit failures

I have purchased three BEME Erod motorized drape systems (one in a previous house, and two in the current house). They have an infrared (IR) remote control that allows you to open and close the blinds at a push of the button, which is very useful if you have things in front of the blinds that make it hard to access the window, or if you just want to be able to open or close your blinds without getting out of bed.

Two of these units have worked flawlessly for several years. My third unit however has had two separate failures which I suspect may be due to poor quality parts.

The first issue crept up slowly, starting out as an intermittent delay in closing. The blind motor would make a “click” when you pressed the close button, but the motor would not engage for 20-60 seconds. Over time, the delay got longer and longer until eventually the blind refused to close. (Although the relay inside would still click when the button on the remote was pressed.)

Diagnosing this as a relay contact failure just from the sounds it made, I opened up the unit, found the part number on the relays, ordered replacements and (for good measure) replaced both relays. (I bought 5 of the relays, so I’m all stocked up for future relay failures.)
two blue relays on a circuit board.

When I had the unit open, I noticed that there was one extra red “re-work” wire on the circuit board, indicating that the PCB had a problem (either a trace left out of the design, or not correctly connected on the PCB during manufacture.) and had to be repaired at the time of manufacture. This is actually more common than you might expect on inexpensive consumer goods, and since the motor was working well with the new relays, I closed things back up.

Around six months later, one night with no prior warning, the motor failed to respond to the remote control completely. No clicking, so the problem probably wasn’t the relays.

Here was my diagnosis procedure:

  • I tried the remote on my other erod (despite the fact that the red light was lighting up when I pushed the buttons) to make sure the remote was working.
  • Because the motor unit was acting as if it was not receiving any power (completely dead), I took the power adapter and tested to make sure it was providing power by using it on my other (working) erod.
  • Now that I had determined that the problem was definitely with the motor unit, and not with the power supply or remote, I disassembled the motor unit.
  • I checked the fuse on the circuit board, as it is the first possible reason power might not get into the circuit, but it was fine. (Also, a small yellow LED on the circuit board was dimly illuminated when plugged in.)
  • I visually checked the capacitors to make sure that none of them were leaking.
  • Since I had a diode tester mode on my multimeter, I checked all the diodes (but didn’t really expect them to have failed….)
  • At this point, I noticed something funky on the circuit board. A small black component had one of it’s legs replaced by a resistor.  (You’ll probably have to zoom into the photo to see it.) Normally, if a resistor is called for in a circuit, it will have its own location on the circuit board. This resistor was definitely added in later in the manufacturing process, and was not part of the original circuit board design.  Since I hadn’t found anything else that would explain the failure, I felt that investigating this part was a good idea.

78L05 power regulator with a resistor replacing it's input leg

  • The part is a 78L05 linear power regulator, which steps the 12v input down to  5 volts suitable for powering the microchips that watch for the IR remote control signal and trigger the relays (via transistors).  The small yellow led was illuminating on the board when power was applied, so the 5 volt power rail should be working….but, the whole resistor leg looked dodgy to me. When I measured the voltage coming out of the 78L05 regulator, it was only 2.7 volts!  (Just enough to illuminate the LED dimly, but not enough to run the other ICs.) After looking up the spec sheet to make sure that it wasn’t a 3.3 volt regulator, and really was supposed to be outputting 5 volts, I knew that either the power regulator was faulty, or something farther into the circuit was drawing so much power that it was not able to provide the proper voltage.
  • I de-soldered the output leg of the power regulator from the rest of the circuit, and the output voltage went up to 5 volts, which hinted that the problem might be farther into the circuit. However, when I tested how much power the regulator could provide, it would only drive 17mA into a short! (A good regulator should provide 100 or 150 mA of power.)

  • I wasn’t sure if the resistor on the input leg was limiting the current that much, so I took the whole thing out and tried powering the regulator directly by bypassing the resistor, and it had the same low output current issue.
  • So, time for a new 78L05 power regulator. This is a VERY common 5 volt regulator, and I happened to have one in-stock, which I soldered back into the circuit. I considered leaving in the input resistor (520 ohm), but decided against it, as the original circuit schematic obviously didn’t have that part, and according to the spec sheet, a 78L05 should be able to go from 12v down to 5v without problems. I measured the idle current draw of the entire motor unit afterwards, and it was only 8 mA, so the voltage regulator is dissipating 12-5 = 7 volts at 8mA, or 0.056 watts (5.6 mWatt) continuously, which is trivial even without a heatsink.

My suspicion is that the factory substituted an “off-brand” (or even counterfeit) 78L05 power regulator which they knew would have trouble dropping 7 volts, so they put a resistor in front of it to drop some of the voltage/power external to the power regulator, but the cheap part still failed.  I’m hopeful that I have now replaced all of the parts that are likely to fail in this unit, and perhaps it will work well for me in the future.

 

 

11 thoughts on “BEME ERod motor drive unit failures

  1. Hey-how were you able to open the rod to replace the motor? Ours seems to be locked and we can’t open it…also doesn’t help that ours is at the top of an 18ft ceiling so it’s hard to get to (we have a ladder of course) Any advice would be appreciated.

    • My unit has a detachable motor. There is a latch on the side of the motor that has to be pulled down, then you can rotate the motor about 45-90 degrees to pull it off of the rod. After you do that, you can open the motor unit with a few screws (or just replace the motor unit entirely if you have a spare.)

  2. Thank you for doing the troubleshooting on the Erod. I have 3 of them and one has the exact same problem as you described. It would make a click sound, then a few minutes later it would open or close the curtains. I noticed that if I press the stop button and then try to open or close, most of the time it will work. But I am worried about it going out one day. I dabble a bit with electronics so I will try to replace that power regulator if I can find one in my spare parts. Thanks again for finding out the problem, especially now that Beme/Erod doesn’t even sell a replacement motor any more.

  3. Hi- I have two of these, and was wondering if you are aware of what triggers the motor to stop when the curtain reaches the opposite end. My issue is that one of rods continue to run even after the curtain is closed, with only way to stop using the remote. To troubleshoot, I swapped the motors and the issue continues with the same rod. Thus eliminating a motor issue. Any leads would be appreciated. Thanks!

    • My belief is that there is a current sensor that detects when the motor starts to draw more current than usual (e.g. because the drape has hit the end of it’s possible motion and the motor has bound up and is no longer turning). When the higher current is detected for a bit of time, it turns off.

      It sounds like yours is not detecting a high current. Normally I would say that this is because the motor electronics / current sensor is bad…but if the issue stays with the rod, and not the motor, my guess would be that something in the rod is “slipping” such that the motor can continue to turn even when the curtain reaches the end, and never draws “too much” current to detect that it’s at the end. (also, be sure to swap the motor power supplies to make sure it’s not an issue with the power supply not being able to deliver “too much” current.)

  4. I really liked this article. The unit, symptoms, weird views, etc. are similar to what I was looking at on the board. I was looking up these erod fixes as the manufacturer no longer sells this unit or replacement parts. My older parents love this unit with the remote as they cannot reach the curtains easy and have no interest in getting a unit with a smartphone app need. And then the unit they have stopped functioning.

    The unit im looking at is acting somewhat close but still different. The open/close functions appear to operate as should only if the desired button is held and then the motor unit is plugged in….I can release the button once it starts moving and it keeps going and then stops when fully open or closed like it should. I can also press the stop button when the movement is in motion and it stops as it should in either direction. But I cannot get it to move again without unplugging the power, holding desired open/close button, and then plugging back in. So if its plugged in without holding a button, it reacts like its not responding to the remote at all. The little led light is also lit as well inside the unit and I can also see the infrared coming off the remote; but don’t have an oscilloscope to check frequency.

    I’m torn on any thoughts here as I only have one motor unit so I can’t really rule out too much here. What bothers me is I question if it does the movement each and every time plugged in; felt like it didn’t start moving a few times. So I’m really torn if the power regulator and/or remote could still be the same problem. I dont know if anyone would have tried the button hold when plugging it in like my folks did; whom are now just doing the button hold and unplugging/plugging.

    Any suggestions would be appreciated. I still may try both the regulator and remote (since seems I can still get that) see what happens.

    • I strongly suspect the problem is with the motor unit controller (and not your remote control).

      I’ve never ran into that particular pattern of misbehavior, so I don’t know exactly what is the issue. Replacing the power regulator would probably be my first thing to try, as they are inexpensive and relatively easy to replace, and an unreliable power supply can cause all kinds of bad behavior.

      • Providing a followup to this. I did try a remote out of curiosity incase and it wasn’t that; the way I acquired the remote i just returned it anyway so it didn’t cost me anything. It was indeed the voltage regulator. I ordered one off a guitar parts website for a few bucks….shipping cost was way more than the part. Electronic part stores I knew of only stocked the higher amperage regulators which these units didnt have room for the larger casings. Appreciated all of these posts and hope these conversations help others as erod stopping marketing these units and no longer sells replacement motors. These are handy units and glad the fix wasn’t bad.

  5. Thanks so much for this detailed fix! I replaced the regulator, and the erod works like brand new again! Would have thrown it out had it not been for your post and easy to follow instructions.

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