1 Topic by chairsgotoschool

  • chairsgotoschool
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Topic: Monoprice maker select thermistor problem

I upgraded the stock extruder to an e3d clone but the temp for the extruder was 110 at room temp. I figured it was a bad thermistor or wrong setting in the firmware so I got some new thermistors, no luck. I have flashed the firmware over a dozen times changing the thermistor type but no luck. when I unplug the thermistor the temp is still around 110 so now i'm thinking this is a problem with the board.

Any ideas on a fix or will I need to buy a new board? everything else works just fine, I would hate to spend $50+ just because it can't read temps right for the extruder.

2 Reply by carl_m1968 (edited by carl_m1968 2017-06-09 20:56:39)

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Re: Monoprice maker select thermistor problem

chairsgotoschool wrote:

I upgraded the stock extruder to an e3d clone but the temp for the extruder was 110 at room temp. I figured it was a bad thermistor or wrong setting in the firmware so I got some new thermistors, no luck. I have flashed the firmware over a dozen times changing the thermistor type but no luck. when I unplug the thermistor the temp is still around 110 so now i'm thinking this is a problem with the board.

Any ideas on a fix or will I need to buy a new board? everything else works just fine, I would hate to spend $50+ just because it can't read temps right for the extruder.


it goes further than you not being able to read it.. The board also will not be able to read the temp and if it is already 110 at room temp then that mean at 290 which would normally be a printing temp your actual temp is only going to be 180. So the board will not be able to control temp either. You could try swapping the connection on the board to the bed thermistor and see if it reads right then. if it still reads high then your board is the issue. What kind of board is it? If it is a RAMPS you don't need both boards you can just buy the RAMPS shield for like $20. The Arduino is a separate board although they are often sold as a pair.

Printing since 2009 and still love it!
Anycubic 4MAX best $225 ever invested.
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3 Reply by chairsgotoschool

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Re: Monoprice maker select thermistor problem

It's a melzi board. and yes swapping to bed still has the same issue. Is there anything I should now about purchasing a new board, or a place to buy them. thanks for the help.

4 Reply by chairsgotoschool

  • chairsgotoschool
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Re: Monoprice maker select thermistor problem

Well I found somewhat of a fix for it. I went in the config file for the firmware and swapped what pins the bed and extruder pull for the thermistor so now the bed doesn't really work but I only use pla so its not a big deal. I was also thinking of using an arduino to handle the bed temp since I have them laying around... I'm cheap.