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260 ° bed temperature
Posted: Tue Nov 20, 2018 12:39 pm
by Picco77
Hello,
I received today my A10m. At start-up the temperature of the bed indicates 260 °. I unplugged the bed connector on the motherboard, and always the same. an idea?
I also connect another NTC and identical.
Thank you.
Re: 260 ° bed temperature
Posted: Tue Nov 20, 2018 7:57 pm
by Gingko
Seems like the hotbed has an open circuit.
Do you have a multimeter? Try to test the continuity of hotbed and the thermistor.
And when hotbed is heating, is the indicator light on the mainboard (D9) light up or not?
Re: 260 ° bed temperature
Posted: Tue Nov 20, 2018 9:24 pm
by Picco77
The display always shows a bed temperature of 257 °.
I tested the NTC on the connector of the bed: the NTC is ok.
I unplugged the connector and tested with a 100K backup NTC. (blue and green wires) in the connector of the motherboard and always displayed at 257 °.
I reloaded the firmware, always the same.
I checked welds and components of the motherboard, I did not see any elements burned or short circuit.
I removed the option from the bed in the firmware to print, but this solution is temporary.
d9 is not lit and no error message.
With 257 °, the bed does not heat up.
Re: 260 ° bed temperature
Posted: Wed Nov 21, 2018 2:05 am
by _kaktus_
Hello.
That we understand each other well.
Gingko suggests that a very high resistance corresponds to such an indication.
Therefore, the question was asked whether you can check if there is no break in the temperature measurement circuit, or not contacts, and not a short circuit.
Can you try a test in this respect
I suggest to check the continuity of connections starting from the soldering pad itself with this signal on the controller board.
And ending with thermistor leads.
Re: 260 ° bed temperature
Posted: Wed Nov 21, 2018 1:02 pm
by Picco77
Hello,
The resistance is fully operational. No open circuit.
Resistance varies well depending on the temperature.
From the bed to the welds on the map everything is ok. I have electronics training.
Re: 260 ° bed temperature
Posted: Sun Nov 25, 2018 9:21 pm
by Tparent
Hello,
I had the same due to an unexpected shortciruit on the noozle temp probe.
Don't believe that you can solve it by your own. I have purchased/replaced the board and it work now.
Re: 260 ° bed temperature
Posted: Wed Nov 28, 2018 11:51 am
by William
Tparent wrote: ↑Sun Nov 25, 2018 9:21 pm
Hello,
I had the same due to an unexpected shortciruit on the noozle temp probe.
Don't believe that you can solve it by your own. I have purchased/replaced the board and it work now.
You are correct!Agreed