Switchmote not getting power [solved]

[nkg22]

Hi,

I got my switchmote assembled and everything looks good while plugged in via FTDI.  The green power LED is lit, and all of the buttons and the relay are working.  When I install the switchmote into the wall, it is not getting power from mains.  I don't see any of the LEDs light up.

I was curious if the switch would work in the wall if it was getting 5v power so I powered the moteino through FTDI, and it is able to control the light switch.  Does this mean that I have a bad connection on the Recom PSU?  Or is the Recom PSU bad? 

Thanks,
Nolan

[Felix]

I would doubt the PSU has anything wrong. Make sure you are wiring it correctly. During assembly I suggest testing the PSU PCB powers from mains before soldering it to the Shield part that has the buttons, because it's easier to debug any issues. But in general the assembly is so easy and with so few parts that it's quite hard to get something wrong, as long as you understand what the parts are and what they do.
Which SwitchMote version do you have?
How are you wiring the mains?

[nkg22]

Yes, I failed to test it from mains before soldering to the shield and I am deeply regretting it     I don't think I can get them apart at this point.

I have the Switchmote R2 and have it wired just as you describe in the guide.  I have the white wire going to neutral and the 2 black wires going to S1 and S2.

[Felix]

Is it the regular SwitchMoteR2 with a single 5A relay or the 2x10A?
For a power up test you only need to wire to N and S1.
If you have a 2x10A then wire neutral to N and HOT in to "HOT".
Check continuity of the fuse and continuity to RECOM's inputs (while not connected to mains!).
FWIW any shorts would be bad for the whole circuit.

[nkg22]

Sorry, it is a regular Switchmote R2 with a single 5A relay.

I'm having trouble checking continuity since all the pins are underneath the PSU and blocked by the shield.

[nkg22]

Thanks again for all your help on this...I think I may have found the disconnect.  I'll see if I can fix it and update this thread.

[nkg22]

At this point I'm pretty sure all my connections are good but it's still not working.  I checked the continuity of:

Fuse	OK
Mains Neutral <-> Recom Neutral	OK
Mains S1 <-> Diode (+)	OK
Diode (-) <-> Recom L	OK

After turning on the breaker I'm still not seeing any 5V power for the Moteino. 

[Felix]

How do you check for "5V on the Moteino"?
Are you tapping into the VIN and GND of the DC side of the circuit?
Can you check for any shorts on the RECOM PSU outputs?
Beware this is mains and while there is isolation through the PSU, don't assume anything with a non functional PSU. Take great care with mains.

Going forward there are 2 options:
- keep debugging yourself attempting to find the issue
- send the unit back and I will debug it and repair or replace it, if there is nothing wrong you need to cover the shipping back to you

[nkg22]

To check for 5v on the Moteino I'm just looking for lights on the Moteino, or for the LEDs on the switchmote assembly to light up.

To test for a short on the RECOM PSU outputs, I tested for continuity between Vo+ and Vo-.  I get a quick chirp when I touch them, but the connection doesn't stay steady.

[Felix]

A visual "5V check" !== multimeter check

Does the green "PWR LED" on the PSU PCB side light up? That should always be ON when powered by FTDI or from mains.

Finally the LEDs on the front panel should come ON as long as the Moteino is programmed with the SwitchMote sketch. If it works when powered via FTDI it should definitely work when powered from mains. Have you checked again that powering via FTDI is still working as expected?

[nkg22]

No, the green 'PWR LED' does not light up when powered from mains.  I just measured DC voltage across Moteino Vin and GND while connected to mains, it was 0V.  When I measured there was a small smark that looked like it came from the RECOM PSU, and the green 'PWR LED' let out a flash.  It went back to it's usual state of not working after that.

Also, yes the moteino is programmed with the SwitchMote sketch, and I did just check again and it's working great while powered via FTDI. 

I'd hate to return it but I'm not sure what else to do at this point.  If you have any other suggestions I'll give them a shot, otherwise I'd like to have it repaired/replaced.

Thanks,
Nolan

[Felix]

Ok, let's return it since I cannot see the unit and don't know what next to suggest. It sounds like the PSU doesn't work.
I will basically power it up, if it's the same behavior, I will start taking it apart to find the culprit. It would be the first RECOM PSU on record that fails, if that's indeed the problem.
Contact me via email at FELIX[at]L0WP0WERLAB[.]C0M for further steps. Sorry about this experience, it's certainly not the norm and I hope we can fix this asap.

[Felix]

This is a case of poor soldering. See photos of what I found between the PSU and the shield, also on the PSU mains interface.
Basically the majority of the solder joints were cold solder joints. The RECOM PSU Neutral pin was floating in the hole, the buttons signals were flaky, the PSU PCB trace from "S2" to the input diode was severed etc. I resoldered all joints. Now only the "S1" port may be used as input, and S2 as output. But it all works.
So this matter is resolved, and there was no issue with the SwitchMote in any way.
This is what the PCBs looked like after I removed some of the wires you had soldered and separated the boards:



Needless to say I spent about half a hour fixing this, testing and putting it back together.