Elk M1 power issues

[chase314]

Hello,

New forum member hoping to get some guidance. I came home tonight and my keypad indicated AC failure and low battery. Opening the cabinet I see that the light on the power supply was off and the system was on battery backup. I switched the board off and the light on the PSU came back on. I disconnected the battery backup and swapped the PSU and got the same behavior. I let the PSU unless the thermal protection kicked on, but still have the same issue. The system was installed by the previous owner and any trouble shooting steps are appreciated.

Thanks,

 

[RAL]

When you refer to the PSU, do you mean the 16VAC wall-wart transformer that powers the M1?
 
It looks like this:
 

 
The first thing I would do is to disconnect the wires at the transformer, and then use a multimeter to measure the voltage that the transformer puts out when it is plugged in.   It should be 16 to 19 volts AC.
 
Next, reconnect the transformer to the M1, and measure the voltage at the M1 input terminals.  It should also be 16-19VAC.  If it's not, that suggests either a bad transformer, or a short somewhere.  The short might be in the wiring between the transformer and the M1, or on the M1 board itself.   Check for loose strands of wire near the M1 input terminals that could cause a short.
 
You say you swapped the PSU... sounds like you have a spare transformer?   If a new transformer didn't work, and turning on the M1 makes the light on the transformer go out, that points back to the wiring or the M1 itself.
 
One more thing to check... remove the plastic top cover from the M1 board and look at the section of the board near the AC input terminals and see if anything looks like it is burned.
 
If you become convinced that the M1 is the problem, you can send the board back to Elk for repair.

 

[mikefamig]

RAL
 
My Elk 16V transformer does not have a light on it. I think that there may be an aux supply involved.
 
Mike.

 

[RAL]

RAL
 
My Elk 16V transformer does not have a light on it. I think that there may be an aux supply involved.
 
Mike.

 
 
Huh - my Elk transformer does have a green LED on it.  You can see it in the lower right corner of the photo in my previous post. Maybe this is  a recent change to the transformer?

 

[mikefamig]

I'm sorry guys, I was sure that there was no light but I just looked ans sure enough there is a green light in the corner of the transformer. Another senior moment.
 
Mike.

 

[chase314]

When you refer to the PSU, do you mean the 16VAC wall-wart transformer that powers the M1?
 
It looks like this:
 

 
The first thing I would do is to disconnect the wires at the transformer, and then use a multimeter to measure the voltage that the transformer puts out when it is plugged in.   It should be 16 to 19 volts AC.
 
Next, reconnect the transformer to the M1, and measure the voltage at the M1 input terminals.  It should also be 16-19VAC.  If it's not, that suggests either a bad transformer, or a short somewhere.  The short might be in the wiring between the transformer and the M1, or on the M1 board itself.   Check for loose strands of wire near the M1 input terminals that could cause a short.
 
You say you swapped the PSU... sounds like you have a spare transformer?   If a new transformer didn't work, and turning on the M1 makes the light on the transformer go out, that points back to the wiring or the M1 itself.
 
One more thing to check... remove the plastic top cover from the M1 board and look at the section of the board near the AC input terminals and see if anything looks like it is burned.
 
If you become convinced that the M1 is the problem, you can send the board back to Elk for repair.

 
Ral,
 
Thank you for the questions/information. Apologies for my delayed response, being a new forum member means I can only post once per today.  You are correct, I was referring to transformers when I said PSU.  Unfortunately, I am pretty sure I know what caused the issue. I recently bought this house and started experiencing issues with the unit not being able to see expansion cards and the log indicated the board was experiencing restarts randomly. I was told that it might be an issue with the Transformer and that swapping it out for a new one might be a good way to eliminate that as a problem.  I didn't realize when I purchased one that there were two identical looking units: 24 Volts used for the trickle charger on the batteries, and the 16.5 Volt one for the main board.  You can see where this is going....
 
I plugged the main board into a 24 volt Transformer weeks ago...and it must have finally burned/shorted something out.  I switched it back out for the original 16.5 Volt transformer and confirm 19 volts on the contacts where they enter the board. When I switch the power on, the light on the Transformer turns off and the voltage drops to nothing...which I'm guessing means that there is a short somewhere. 
 
I'm guessing you mean the black cover with the schematics that covers the majority of the board. I will try to remove this tomorrow to see if I can see any obvious damage. Do you know if these boards have any mechanisms to protect against over voltage, or is it likely that I fried something permanently? The backup battery power still works...so the board itself isn't dead overall. 
 
Thanks in advance for any additional information/help. Unfortunately, I inherited a pretty elaborate setup when I bought this house and am learning as i go. 
 
Regards, 

 

[mikefamig]

I would try replacing the 16 volt power supply to the panel next. The supply could be failing when you apply a load to it.
 
Mike.

 

[RAL]

Ral,
 
Thank you for the questions/information. Apologies for my delayed response, being a new forum member means I can only post once per today.  You are correct, I was referring to transformers when I said PSU.  Unfortunately, I am pretty sure I know what caused the issue. I recently bought this house and started experiencing issues with the unit not being able to see expansion cards and the log indicated the board was experiencing restarts randomly. I was told that it might be an issue with the Transformer and that swapping it out for a new one might be a good way to eliminate that as a problem.  I didn't realize when I purchased one that there were two identical looking units: 24 Volts used for the trickle charger on the batteries, and the 16.5 Volt one for the main board.  You can see where this is going....
 
I plugged the main board into a 24 volt Transformer weeks ago...and it must have finally burned/shorted something out.  I switched it back out for the original 16.5 Volt transformer and confirm 19 volts on the contacts where they enter the board. When I switch the power on, the light on the Transformer turns off and the voltage drops to nothing...which I'm guessing means that there is a short somewhere. 
 
I'm guessing you mean the black cover with the schematics that covers the majority of the board. I will try to remove this tomorrow to see if I can see any obvious damage. Do you know if these boards have any mechanisms to protect against over voltage, or is it likely that I fried something permanently? The backup battery power still works...so the board itself isn't dead overall. 
 
Thanks in advance for any additional information/help. Unfortunately, I inherited a pretty elaborate setup when I bought this house and am learning as i go. 
 
Regards, 

 
I can't say for sure, but I'm thinking that the 24V transformer may have damaged the M1's power supply circuitry on the board.  The good news would be that the rest of the M1 beyond the power supply circuitry sounds like it is
ok, since it still runs with the battery.
 
I believe there is a MOV across the AC input on the M1 board.  It may be that the too-high voltage caused the MOV to short out (which is what it's supposed to do in case of a voltage surge) and that's all that's wrong.   It's also possible that the voltage regulator that converts the AC to DC got smoked.   If that's all that got damaged, it's not a terrible thing to repair.

 

[EyeofSauron]

I would try replacing the 16 volt power supply to the panel next. The supply could be failing when you apply a load to it.
 
Mike.

 
I'd start with this.  Plenty of failing power-supplies give you a nominal reading when placed on a meter, but die when you test them under load. 
 
And those transformers are a common item to go bad.  Fortunately, replacements are cheap.