Problem with Mosfets on RAMPS 1.4 board
Posted by doniboy
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Re: Problem with Mosfets on RAMPS 1.4 board April 09, 2014 07:18AM |
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olisoft
did you connect the power supply to both connectors on your ramps?
yes I did connect my power supply the right way (I'm using a ATX 500W power supply)
Quote
waitaki
The mosfets do not control the motors, the Pololu drivers do that. Also, those LED's belong to the heater, bed and fan circuit. Or am I misunderstanding you?
I think you are. I meant to say that my motors are working completely fine (btw I use stepstick DRV8825 drivers) but D10, D9 & D8 won't go off (they keep putting 12V out of the terminals) and led 3 and 4 won't go off but somehow led 2 won't go on
And I think the problem has to do with one or maybe all of the mosfets
Edited 1 time(s). Last edit at 04/09/2014 07:19AM by doniboy.
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Re: Problem with Mosfets on RAMPS 1.4 board April 10, 2014 12:52PM |
Hi,
I checked the voltage coming from the arduino (pin 8, 9 and 10) and they are 0V (so probably not a firmware related problem).
Then I unplugged the arduino from the RAMPS board (of course I first turned the power off) and when I turned the power back on the led's where still the same (led 3 an 4 on, led 2 off).
So the mosfets somehow turn itself on.
I also measured the voltage on the mosfet gate pin (the most left pin) and this is what I found out: mosfet Q1 0.6V, mosfet Q2 0.6V and mosfet Q3 0V (this is probably why led 2 isn't on).
I checked the screw terminals as well: D10 10.9V, D9 10.9V and D8 12.15V
The voltage from my power supply is 12.16V
BTW I did soldered a bare RAMPS 1.4 board which I bought here http://reprapworld.com/?products_details&products_id=54&cPath=1591_1609
I checked the voltage coming from the arduino (pin 8, 9 and 10) and they are 0V (so probably not a firmware related problem).
Then I unplugged the arduino from the RAMPS board (of course I first turned the power off) and when I turned the power back on the led's where still the same (led 3 an 4 on, led 2 off).
So the mosfets somehow turn itself on
.I also measured the voltage on the mosfet gate pin (the most left pin) and this is what I found out: mosfet Q1 0.6V, mosfet Q2 0.6V and mosfet Q3 0V (this is probably why led 2 isn't on).
I checked the screw terminals as well: D10 10.9V, D9 10.9V and D8 12.15V
The voltage from my power supply is 12.16V
BTW I did soldered a bare RAMPS 1.4 board which I bought here http://reprapworld.com/?products_details&products_id=54&cPath=1591_1609
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Re: Problem with Mosfets on RAMPS 1.4 board April 14, 2014 10:42AM |
hey,
this weekend I desolderd the mosfets and performed some tests on them.
When I connect a switch coming from -3V to pin 1 (viewed from the from so where the black box is) en connect a led also from -3V to pin 2 and finally I connect the +3V to pin 3.
When I press the switch the led goes off and when I release the switch it goes back on.
Is this wright?
I also checked the voltages on the places where the mosfets used to be with the negative probe on ground:
Q1: pin1 0V, pin2 10.6V, pin3 0V
Q2: pin1 0V, pin2 10.6V, pin3 0V
Q3: pin1 0V, pin2 0V, pin3 0V
I also checked the voltages between the pins of the mosfets:
Q1: pin1-pin2 9.68V/ pin2-pin3 10.64V/ pin1-pin3 0V
Q2: pin1-pin2 9.69V/ pin2-pin3 10.63V/ pin1-pin3 0V
Q3: pin1-pin2 0V/ pin2-pin3 0V/ pin1-pin3 0V
D10, D9 & D8 all measure 0V (obviously)
On the mosfets is this code: A large F followed by; 1B42AR LM7805C
Hope you understand all the data, it is a bit confusing to me
this weekend I desolderd the mosfets and performed some tests on them.
When I connect a switch coming from -3V to pin 1 (viewed from the from so where the black box is) en connect a led also from -3V to pin 2 and finally I connect the +3V to pin 3.
When I press the switch the led goes off and when I release the switch it goes back on.
Is this wright?
I also checked the voltages on the places where the mosfets used to be with the negative probe on ground:
Q1: pin1 0V, pin2 10.6V, pin3 0V
Q2: pin1 0V, pin2 10.6V, pin3 0V
Q3: pin1 0V, pin2 0V, pin3 0V
I also checked the voltages between the pins of the mosfets:
Q1: pin1-pin2 9.68V/ pin2-pin3 10.64V/ pin1-pin3 0V
Q2: pin1-pin2 9.69V/ pin2-pin3 10.63V/ pin1-pin3 0V
Q3: pin1-pin2 0V/ pin2-pin3 0V/ pin1-pin3 0V
D10, D9 & D8 all measure 0V (obviously)
On the mosfets is this code: A large F followed by; 1B42AR LM7805C
Hope you understand all the data, it is a bit confusing to me
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Re: Problem with Mosfets on RAMPS 1.4 board April 15, 2014 10:41AM |
I bought this kit complete from reprapworld.com
I even went to the store to buy it instead of ordering it.
But how come that went I wire the mosfet/voltage regulator as a voltage regulator (so +9v to left pin and -9v to middle pin) the heatsink (backside) goes VERY hot in a short time?
I probably drop by reprapworld.com again to ask for a replacement.
here's a pic of the same mosfet or whatever it may be that I have:
Edited 1 time(s). Last edit at 04/15/2014 10:55AM by doniboy.
I even went to the store to buy it instead of ordering it.
But how come that went I wire the mosfet/voltage regulator as a voltage regulator (so +9v to left pin and -9v to middle pin) the heatsink (backside) goes VERY hot in a short time?
I probably drop by reprapworld.com again to ask for a replacement.
here's a pic of the same mosfet or whatever it may be that I have:
Edited 1 time(s). Last edit at 04/15/2014 10:55AM by doniboy.
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Re: Problem with Mosfets on RAMPS 1.4 board April 22, 2014 11:05AM |
o sorry I messed up a little bit in my comment.
I meant to say that when I press "Heat" in pronterface (so not "Bed") , D8 turns on I measure 12V and see LED2 light up.
When I turn the FAN on with the M106 command LED3 goes on and D9 puts out 12V
So, I don't use a heated-bed and I'm not planning to use one so that's why I changed the board number in marlin (configuration.h) to 35 what means that I have 2 fans and 1 hot-end, this is also the reason why I can't use the "bed" button to turn D10 on (I don't have a heated-bed).
So we should think that there is a option to turn that second fan on (also known as D10) but I can't find it.
I'm trying to find out where the commands are in the firmware but it is hard to find.
I meant to say that when I press "Heat" in pronterface (so not "Bed") , D8 turns on I measure 12V and see LED2 light up.
When I turn the FAN on with the M106 command LED3 goes on and D9 puts out 12V
So, I don't use a heated-bed and I'm not planning to use one so that's why I changed the board number in marlin (configuration.h) to 35 what means that I have 2 fans and 1 hot-end, this is also the reason why I can't use the "bed" button to turn D10 on (I don't have a heated-bed).
So we should think that there is a option to turn that second fan on (also known as D10) but I can't find it.
I'm trying to find out where the commands are in the firmware but it is hard to find.
//// The following define selects which electronics board you have. Please choose the one that matches your setup // 3 = MEGA/RAMPS up to 1.2 = 3 // 33 = RAMPS 1.3 / 1.4 (Power outputs: Extruder, Fan, Bed) // 34 = RAMPS 1.3 / 1.4 (Power outputs: Extruder0, Extruder1, Bed) // 35 = RAMPS 1.3 / 1.4 (Power outputs: Extruder, Fan, Fan) #ifndef MOTHERBOARD #define MOTHERBOARD 35 #endif // Define this to set a custom name for your generic Mendel, //#define CUSTOM_MENDEL_NAME "" // Define this to set a unique identifier for this printer, (Used by some programs to differentiate between machines) // You can use an online service to generate a random UUID. (eg [www.uuidgenerator.net]) // #define MACHINE_UUID "00000000-0000-0000-0000-000000000000" // This defines the number of extruders #define EXTRUDERS 1 //// The following define selects which power supply you have. Please choose the one that matches your setup // 1 = ATX // 2 = X-Box 360 203Watts (the blue wire connected to PS_ON and the red wire to VCC) #define POWER_SUPPLY 1 // Define this to have the electronics keep the power supply off on startup. If you don't know what this is leave it. // #define PS_DEFAULT_OFF
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Re: Problem with Mosfets on RAMPS 1.4 board April 24, 2014 04:53AM |
I hope somewone reads this and fixes the bug because I don't know if I have the skills to fix it
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I think I'm gona use one PWM fan and leave one on the whole time, maybe that I can use the 12v-aux that is placed behind D2.
.I think I'm gona use one PWM fan and leave one on the whole time, maybe that I can use the 12v-aux that is placed behind D2.
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