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Bed Not Heating  

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ARAMP1
(@aramp1)
Eminent Member
Bed Not Heating

I swapped the bed and hot end thermistor to confirm the thermistor is working correctly and it is.  All fuses are good.  What is the next step to troubleshoot?  

Posted : 26/07/2024 6:07 am
Eef
 Eef
(@eef)
Reputable Member
RE: Bed Not Heating

Is the led on the heatbed working? If yes, you have power on the heat element. 
Most easy it to get a multimeter and start measuring voltage. 
Start on the heatbed. If no voltage. Follow the wires back to the board. 
There could be a bad connection
If you have voltage on the heatbed, (and the led lights up) your heater is broken. 

 

We will do what we have always done. We will find hope in the impossible.

Posted : 27/07/2024 8:18 pm
ARAMP1
(@aramp1)
Eminent Member
Topic starter answered:
RE: Bed Not Heating

Thanks for the reply.  The LED isn't lit.  There's no voltage at the heatbed so I went back to the lugs on the board and there's no voltage there either.  

Bad board?

Posted : 29/07/2024 8:40 pm
Eef
 Eef
(@eef)
Reputable Member
RE: Bed Not Heating

First more checks: 
- The power on the heatbed can only be measured, when there is a command to heat the heatbed. 
In the LCD menu -> Preheat (choose any option). Check if on the LCD it says: Heating. 
- Do the selftest (this also tests the heaters). 
This could give more information. 
- Any firmware updates done? 

 

We will do what we have always done. We will find hope in the impossible.

Posted : 29/07/2024 9:33 pm
ARAMP1
(@aramp1)
Eminent Member
Topic starter answered:
RE: Bed Not Heating

Yes, when pre-heating, there's zero voltage at the lugs on the motherboard. 

 

As for firmware, I think I'm on 3.12.2.  Have been needing to update firmware for a while.  

Posted : 29/07/2024 10:05 pm
ARAMP1
(@aramp1)
Eminent Member
Topic starter answered:
RE: Bed Not Heating

And to clarify, this problem was found when doing a self test.  I changed out the nozzle and was running the wizard when I found this.  

Posted : 29/07/2024 10:18 pm
ssmith
(@ssmith)
Trusted Member
RE: Bed Not Heating

There's a fuse in the circuit, before the voltage lugs....

Posted : 29/07/2024 11:20 pm
ARAMP1
(@aramp1)
Eminent Member
Topic starter answered:
RE: Bed Not Heating

Hmmmm. That was the first thing i checked and and all three circuit breakers on the board are good. 

Posted : 29/07/2024 11:51 pm
Eef
 Eef
(@eef)
Reputable Member
RE: Bed Not Heating

The blue 15A fuse is for Bed heating.
If the fuse is GOOD and there is a problem on the board or in the logic of the system, then during the heating. Both sides of the fuse have low/no voltage. And next step would be to search if it is the board or the logics (firmware).
If the fuse is BAD, and there is NO problem on the board or in the logic of the system,  then during heating, one side is low and the other high. 
Then the searching has to be done after the Fuse. 
So would be good to measure these voltages during a command (preheat bed). 

We will do what we have always done. We will find hope in the impossible.

Posted : 30/07/2024 4:54 am
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