Hi,
Moderately established machine, had a blow out. Replaced the entire assembly with SeeMeCNC hot end.
Symptoms and Tests:
1. No voltage coming off of the board.
2. Fuses all good (replaced both 5A fuses, big 15A had continuity)
3. No shorts between heat cartridge and hot end.
4. Continuity from the leads at the board all the way to the heat cartridges.
5. Heated bed heats.
Blown board? (Hope not.)
Anything else I can test?
Hot End Not Working
Hot End Not Working
Technologist, Maker, Willing to question conventional logic
http://dropc.am/p/KhiI1a
http://dropc.am/p/KhiI1a
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Polygonhell
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Re: Hot End Not Working
Does the LED come on?
Do you get a sensible temperature reading at room temperature? If you don't the firmware will prevent it heating?
The mosfet circuit is pretty simple, you have a PWM signal coming into the middle leg that attenuates the 12V across the outer legs (more or less).
You can test the 5V coming into the mosfet with a volt meter, you might have to bridge it to ground with a capacitor to get a clean signal on a digital meter, it might not read 5V, you're looking for something other than 0 when the hotend is supposed to be heating.
Do you get a sensible temperature reading at room temperature? If you don't the firmware will prevent it heating?
The mosfet circuit is pretty simple, you have a PWM signal coming into the middle leg that attenuates the 12V across the outer legs (more or less).
You can test the 5V coming into the mosfet with a volt meter, you might have to bridge it to ground with a capacitor to get a clean signal on a digital meter, it might not read 5V, you're looking for something other than 0 when the hotend is supposed to be heating.
Printer blog http://3dprinterhell.blogspot.com/
Re: Hot End Not Working
Does the LED come on?
Nope.
Do you get a sensible temperature reading at room temperature? (If you don't the firmware will prevent it heating.)
Yes, the temperature is reading at the same start temp as the heated bed. Shooting compressed air reduces the temperature indicated.
The mosfet circuit is pretty simple, you have a PWM signal coming into the middle leg that attenuates the 12V across the outer legs (more or less).
You can test the 5V coming into the mosfet with a volt meter, you might have to bridge it to ground with a capacitor to get a clean signal on a digital meter, it might not read 5V, you're looking for something other than 0 when the hotend is supposed to be heating.
Whoah, this is above the line! I'll just order a new board and resolve this issue when I'm not jonesing to print. It is more than likely a blown MOSFET. (hmmm, time v. money, in this case time wins. Get the board, fix the old one later.)
Further discussions with John:
It's possible to change the power and thermister to use Extruder 1 instead of Extruder 0. The power is held in reserve for a fan; however, that is easily switched. I'll do that while I'm waiting for my replacement board. John mentioned that the pins.h should be changed in the firmware to indicate to indicate the other extruder is in use.
Nope.
Do you get a sensible temperature reading at room temperature? (If you don't the firmware will prevent it heating.)
Yes, the temperature is reading at the same start temp as the heated bed. Shooting compressed air reduces the temperature indicated.
The mosfet circuit is pretty simple, you have a PWM signal coming into the middle leg that attenuates the 12V across the outer legs (more or less).
You can test the 5V coming into the mosfet with a volt meter, you might have to bridge it to ground with a capacitor to get a clean signal on a digital meter, it might not read 5V, you're looking for something other than 0 when the hotend is supposed to be heating.
Whoah, this is above the line! I'll just order a new board and resolve this issue when I'm not jonesing to print. It is more than likely a blown MOSFET. (hmmm, time v. money, in this case time wins. Get the board, fix the old one later.)
Further discussions with John:
It's possible to change the power and thermister to use Extruder 1 instead of Extruder 0. The power is held in reserve for a fan; however, that is easily switched. I'll do that while I'm waiting for my replacement board. John mentioned that the pins.h should be changed in the firmware to indicate to indicate the other extruder is in use.
Technologist, Maker, Willing to question conventional logic
http://dropc.am/p/KhiI1a
http://dropc.am/p/KhiI1a