Intermittently stops printing
Posted: Thu Sep 24, 2020 10:53 pm
Hi All
I have been having a problem with the Geeetech a10m that I own. The printer every now and again appears to stop while printing. It can stop printing at start mid or the very end of a print. It does not seem to be much consistency as to when it stops printing. It occurs when I print using the SD card or via USB. I am hoping that someone give me some guidance as to what’s occurring or confirm some of the things that I have found. I am hoping this will help someone who has same problem.
What occurs is the printer stops and the main screen on the printer just flashes with the background being eliminated. The led within the 3D touch also flashes. There is no data displayed on the screen at that point and the printer no longer response to any input. The bed heater and also the nozzle heater both turn off.
However, if I turn that power on and off (power cycle) the printer works fine, until the next time it stops printing. Now that can actually happen a couple times in the row or last week before it actually stops and gets into this state. I have upgraded the ROM and I am I am currently using Marlin 2.0 from Vert (https://github.com/Vertabreak) and this works as expected. When the actual printer works I’m getting perfectly fine prints.
I’ve taken a video of the printer and what happens when the printer stops. I’ve put it on YouTube. (https://youtu.be/cGARr_YOHak). In the video the printer stops and you can see the LEDs are all on and I panned to see the heater bed LED is off and then I power cycle the printer. Then you can read the LCD screen.
Now I have been doing some investigation and reading many of the postings within this forum and others. I have a copy of the circuit diagram for the GT2560 V3.0 which I have been tracing through to understand what is occurring.
First diagnosis was I did consider it could be the power supply. When the fault actually occurs I have done some testing.
I have measured the voltage (volt meter) coming from the power supply and also on the main board and found that both cases of 24 volts. Similarly, if you look at the circuit diagram you’ll notice that there are two LEDs indicating if there is voltage. These two LEDs are D6 and D16. D6 is the 12 volts for the heater bed and the other is VDC that is input to the voltage regulator MP2303A. If I am printing using the USB I use CURA. So when this error occurs the printer can no longer communicate via the USB.
The LED for the heat bed, D9, is turned on when the heat bed is heating up and when it has reached temperature the LED will flash (turn on turn off) to maintain temperature for the heat bed. When this fault occurs the LED for the heat bed, D9, turns off and no longer flashes. This indicates that the controller is no longer turning the power MOSFET, NMOS3, on to heat the bed heater. I have not actually measured the output coming from PWM3 from the controller using an oscilloscope.
So now if I reset (power cycle) the printer comes back and works perfectly well for a time.
Has anyone had the same issues with their GT2560 V3.0 board like this?.
I think there are three possibilities. I’ve worked through them below the first one being the most likely.
1. Bad capacitor
Within these forums I’ve only found one person that indicated that this has been an issue. So with all my work it indicates to me that it is likely to be a capacitor that is going bad and dropping voltage enough to reset the processor but find once voltage’s been removed. In this case I am thinking it is likely to be C138, 100uF. If you examine the next version of this board GT2560 V3.1 C138 has been replaced with a large capacitor. When the fault occurs the screen flickers and the LED in the 3D touch also flickers, PB5 control line from the processor. Similarly, the control line LED from the processor also toggles with LED, L, next to the crystal also flashes.
2. Bad processor / ROM
If the processor is faulting due to something is wrong with the ROM that has been installed then this behaviour of resetting the processor, intermittently, would have the same behaviour. This could be a hardware fault within the processor or it could be a software fault the ROM that has been installed. I have tried a number of versions of ROM using Marlin 2.0 and a number of versions of Marlin 1.1.9 including the stock ROM. Vert's ROMs are pretty good so....
3. Bad power supply
Although the power supply provides 24 V and I have also tested it also could momentarily change voltage due to a short or issues with large current draw. This large current draw could be from the heater bed. I have tested this by turning the heater bed off during printing but the error still occurs.
If anyone’s got a bit to add I would love to hear from so we can actually have an archive on how to solve problems like this one.
- Phil
I have been having a problem with the Geeetech a10m that I own. The printer every now and again appears to stop while printing. It can stop printing at start mid or the very end of a print. It does not seem to be much consistency as to when it stops printing. It occurs when I print using the SD card or via USB. I am hoping that someone give me some guidance as to what’s occurring or confirm some of the things that I have found. I am hoping this will help someone who has same problem.
What occurs is the printer stops and the main screen on the printer just flashes with the background being eliminated. The led within the 3D touch also flashes. There is no data displayed on the screen at that point and the printer no longer response to any input. The bed heater and also the nozzle heater both turn off.
However, if I turn that power on and off (power cycle) the printer works fine, until the next time it stops printing. Now that can actually happen a couple times in the row or last week before it actually stops and gets into this state. I have upgraded the ROM and I am I am currently using Marlin 2.0 from Vert (https://github.com/Vertabreak) and this works as expected. When the actual printer works I’m getting perfectly fine prints.
I’ve taken a video of the printer and what happens when the printer stops. I’ve put it on YouTube. (https://youtu.be/cGARr_YOHak). In the video the printer stops and you can see the LEDs are all on and I panned to see the heater bed LED is off and then I power cycle the printer. Then you can read the LCD screen.
Now I have been doing some investigation and reading many of the postings within this forum and others. I have a copy of the circuit diagram for the GT2560 V3.0 which I have been tracing through to understand what is occurring.
First diagnosis was I did consider it could be the power supply. When the fault actually occurs I have done some testing.
I have measured the voltage (volt meter) coming from the power supply and also on the main board and found that both cases of 24 volts. Similarly, if you look at the circuit diagram you’ll notice that there are two LEDs indicating if there is voltage. These two LEDs are D6 and D16. D6 is the 12 volts for the heater bed and the other is VDC that is input to the voltage regulator MP2303A. If I am printing using the USB I use CURA. So when this error occurs the printer can no longer communicate via the USB.
The LED for the heat bed, D9, is turned on when the heat bed is heating up and when it has reached temperature the LED will flash (turn on turn off) to maintain temperature for the heat bed. When this fault occurs the LED for the heat bed, D9, turns off and no longer flashes. This indicates that the controller is no longer turning the power MOSFET, NMOS3, on to heat the bed heater. I have not actually measured the output coming from PWM3 from the controller using an oscilloscope.
So now if I reset (power cycle) the printer comes back and works perfectly well for a time.
Has anyone had the same issues with their GT2560 V3.0 board like this?.
I think there are three possibilities. I’ve worked through them below the first one being the most likely.
1. Bad capacitor
Within these forums I’ve only found one person that indicated that this has been an issue. So with all my work it indicates to me that it is likely to be a capacitor that is going bad and dropping voltage enough to reset the processor but find once voltage’s been removed. In this case I am thinking it is likely to be C138, 100uF. If you examine the next version of this board GT2560 V3.1 C138 has been replaced with a large capacitor. When the fault occurs the screen flickers and the LED in the 3D touch also flickers, PB5 control line from the processor. Similarly, the control line LED from the processor also toggles with LED, L, next to the crystal also flashes.
2. Bad processor / ROM
If the processor is faulting due to something is wrong with the ROM that has been installed then this behaviour of resetting the processor, intermittently, would have the same behaviour. This could be a hardware fault within the processor or it could be a software fault the ROM that has been installed. I have tried a number of versions of ROM using Marlin 2.0 and a number of versions of Marlin 1.1.9 including the stock ROM. Vert's ROMs are pretty good so....
3. Bad power supply
Although the power supply provides 24 V and I have also tested it also could momentarily change voltage due to a short or issues with large current draw. This large current draw could be from the heater bed. I have tested this by turning the heater bed off during printing but the error still occurs.
If anyone’s got a bit to add I would love to hear from so we can actually have an archive on how to solve problems like this one.
- Phil