Hotend temperature fluctuations May 16, 2019 04:01AM |
Registered: 10 years ago Posts: 231 |
Re: Hotend temperature fluctuations May 16, 2019 05:24AM |
Admin Registered: 11 years ago Posts: 3,096 |
Re: Hotend temperature fluctuations May 16, 2019 05:35AM |
Registered: 10 years ago Posts: 231 |
Quote
Ohmarinus
Just going out on a limb here and suggest that it might be a faulty MOSFET? Or maybe a break in the solder of the MOSFET?
Check the soldering of the MOSFET and see if it came loose somewhere. I don't know how you can check if a MOSFET has gone bad, but that's where I would check. Maybe just replace the thing since it's a cheap component anyway.
If it was a PSU issue, you would first notice this on the heated bed since that one pulls way more Amps. However, fluctuation on a heated bed is less noticeable since it has a larger thermal mass. But I suspect the MOSFET.
Re: Hotend temperature fluctuations May 16, 2019 08:31AM |
Admin Registered: 11 years ago Posts: 3,096 |
Quote
brucehvn
Quote
Ohmarinus
Just going out on a limb here and suggest that it might be a faulty MOSFET? Or maybe a break in the solder of the MOSFET?
Check the soldering of the MOSFET and see if it came loose somewhere. I don't know how you can check if a MOSFET has gone bad, but that's where I would check. Maybe just replace the thing since it's a cheap component anyway.
If it was a PSU issue, you would first notice this on the heated bed since that one pulls way more Amps. However, fluctuation on a heated bed is less noticeable since it has a larger thermal mass. But I suspect the MOSFET.
Hi Ohmarinus,
You mean the MOSFET on the Ramps board? Like I said before, I've actually tried three different Mega and Ramps boards in the effort to figure it out. My bed is a 12v silicon heater which I forgot has it's own control board and MOSFET which could be why I don't see any fluctuation there, but since I've tried different Ramps boards with no change, I'm guessing it's not related to that.
Re: Hotend temperature fluctuations May 16, 2019 09:56AM |
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Re: Hotend temperature fluctuations May 16, 2019 03:31PM |
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Re: Hotend temperature fluctuations May 16, 2019 08:06PM |
Registered: 10 years ago Posts: 231 |
Quote
dc42
Sudden erratic jumps in temperature readings are usually caused by bad connections to the thermistor, or a thermistor wire touching the hot end metalwork coupled with leakage in the heater cartridge. Just possibly by a faulty thermistor.
Re: Hotend temperature fluctuations May 17, 2019 04:51AM |
Admin Registered: 11 years ago Posts: 3,096 |
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brucehvn
Quote
dc42
Sudden erratic jumps in temperature readings are usually caused by bad connections to the thermistor, or a thermistor wire touching the hot end metalwork coupled with leakage in the heater cartridge. Just possibly by a faulty thermistor.
Hi dc42,
That was my first thought, but I've got two thermistor cartridges and they show the same behavior. Unless I got two bad ones from E3D, it appears to be something else. The heater block has a silicon sock and I've made sure the wires are not trapped underneath or rubbing against anything hot. The wires pretty much come straight out away from the heater block. I'm swapping out the thermistor cable and trying one last mega board today and we'll see how that goes.
Re: Hotend temperature fluctuations May 17, 2019 07:41AM |
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Re: Hotend temperature fluctuations May 17, 2019 09:24AM |
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Re: Hotend temperature fluctuations May 18, 2019 01:38PM |
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Re: Hotend temperature fluctuations May 19, 2019 05:13AM |
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Re: Hotend temperature fluctuations May 05, 2020 10:29AM |
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Re: Hotend temperature fluctuations May 05, 2020 04:36PM |
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Re: Hotend temperature fluctuations May 25, 2020 01:48PM |
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