I have been printing pla without a problem and working to perfect the print quality by printing boats and cubes. All of a sudden I lost both the hot end temperature and the heated base printer plate. I tried all the normal shut down, reboot and start over but get a min temp error on the reprap screen. I can’t figure why both and dead. I replaced the hot end heater last week and it and the thermistor both seemed to work. The base plate was working fine. I am getting 12vt at the power supply and at both sides of the green plug.
How can I test the Arduino/Ramps board? Would a bad thermistor stop power to both heaters? Does the RepRap control screen operate independently than the Ramps? I can’t get heat on either one using the control screen. Are there other pins I can I test or should
I just replace the board and move forward? If I install a new board, do you have the link to
Update my Arduino with Ryan’s version? What are the control points for the 12vt feeds?
Any help would be appreciated.
Rand
In my (limited) experience, Min Temp means the thermistor shorted or got disconnected. Without a valid temp reading the electronics will not turn on the heaters. If there’s nothing obviously wrong at the RAMPS where the thermistors plug in, look really closely around the heater block and on the heater bed where the thermistor connects to whatever wiring carries that signal to the control board. Look for twists right next to the glass bead - a couple of times that’s been my issue.
Can you “ohm out” the thermistor connections to see if they’re shorted?
RAMPS 1.4 has 2 power inputs, one is dedicated for the heated bed, and has an 11A fuse. The other power input has a 6A fuse and powers the logic as well.as hotend heaters.
If you lost both heaters, something else is going on. Ate you sure its the heaters and not the thermistor channel? I guess you get the error.and it refuses to even try to turn on the heaters.
In this case I’d suspect the analog input pins on your Mega2560, or the power to the thermistor channels, assuming that the thermistors are still properly plugged in with good connection.
The heaters themselves are quite well separated, so it’s way more likely to be a sensor issue.
The thermistors are read by suppling 5V to one lead (check the voltage on the pins) as a part of a voltage divider network with a known value resistor to feed an analog input. One leg of the thermistor pin should show voltage with the board powered up.
I just had this problem. I was messing with the thermistor on my Hemera hotend and I guess I messed it up because when I went to heat up the hotend I was getting “temp reading error”. So my advice would be to replace the thermistor and see if that fixes it.
I found that the heater I got had a shorted thermistor. This happened because the screw that holds it into the heater block had been tightened too much and cut through the insulation of the thermistor wires. I re-insulated the wires and everything was working again. Someone was just too enthusiastic at the assembly factory.
Mike B.
tom that’s exactly what i found . Now I have to get the soldering iron out again. I’ll let you know when i have heat……
thanks
rand
Dan
thanks again for for your help you were exactly correct and confirmed what i found… i had 5vt on both sensors but no resistance on the hot end thermistors. I am fixing the wires and will confirm that fixed the problem. I think the one thermistor failure causes both heater limits to fail because of min error limit but I’m guessing.
Hopefully I’ll be printing soon.
thanks
rand
Spent several hours doing a professional wiring job installing a new heater for the hot end. New military connections, shielded cover and marine shrink wrapped cable ends. I expected it to now be perfect………. Three hours later I still couldn’t get the printer to start up it kept shutting down half way the cycle.
Finally - I saw that the thermistor was not deep into the heater (this one from China) didn’t have a screw to hold it in.
I wasn’t getting a good signal and the temp parameters were not being met.
The results was very frustrating and inconsistent…… when I put the thermistor in deep it seems to work. I am still getting funny signals from the heated base plate. It used to turn on before the hot end and when satisfied the hot end would catch up. Now the heated base only comes on sometimes and doesn’t really respond like before.
Does anyone have a new link for Ryan’s software and the procedure to flash a new Arduino Mega? I’m thinking that I may have had voltage spikes or overheating? I have several Arduinos but would have to flash the duplicate files. I haven’t done it for years and would need step by step instructions.
Thanks again for helping
Rand
Last time I flashed Marlin on a Mega2560 I used the Arduino IDE on Linux because the Windows one doesn’t work anymore.
Platformio should work and be able to flash it to the board as well.
You can find the firmware in the marlinbuilder releases page. I think that the firmware on there assumed Mk8 extruder and DRV8825 drivers set to 32X microstepping.
If the default settings work, you can flash it without using arduino or platformio. You just flash it using xloader.
You can also do M503 to show most (if not all) of the current settings on your current board. M502 will restore the defaults (in case a strange PID setting or something is causing your issue) and if you like the settings you’re using, M500 will save them through a restart. I would do M503 and save those in a file somewhere and then do M502 and test a few times before swapping out the board.
Jeff: I am very inexperienced. With the Arduino software. Where do you enter these M500 codes? I loaded x loader but need instructions on how to copy and move a file to another Arduino. I am very afraid to touch the software if I don’t know what I am doing. Does Ryan have the exact file we used years ago that he could link?
I’m chasing a variety of errors that come randomly and go away. Print not coming on, movements odd and a different size ratio than called out.
The Repetier program is performing very odd. Could I have a problem of interference from the cables, boards power supply? What needs to be shielded? I have a typical installation with the Arduino in a cooled box and the power supply sits 18” away. What creates random signals versus a bad Arduino board?
Thank you
Rand
Do you use Repetier host? You can send them from that. And you can see the results in the console.
There have been dozens, if not hundreds of versions. Why do you want to use the older files?
Well, we need to focus on them one at a time, describe them in detail and see if we can solve them. I have forgotten all about the older firmware. So I would rather you start with something new. But I don’t honestly even know what your machine does. You keep saying print. Do you have an extruder installed on it? The new firmware is only for CNC.
Odd how? All those things can be broken. But it is more likely there is a simple reason for all of this.
The first step getting RH to work is to just connect it and check that the console is printing useful info. You can paste the console here and we can look at it. If you don’t see anything, try sending M115, which asks for the version information.
Interference (random signals) is pretty rare. We need to eliminate everything else as a cause first.
Morning Jeff,
I lost you - how do I enter the G500 code? I have put it into Repetier but it doesn’t do anything when I send it. If I load a file half the time the temp doesn’t show up and therefore doesn’t start the print program. My heated bed also only works part of the time - it seems I have a bad component/chip/plug/wire/sensor or something is related to the temperature sensing part of the board?
Rand
I asked a few questions. It really help if you take the time to answer them.
M500 (not G500) doesn’t do anything on its own. M503 will print the settings you have.
Hi Jeff,
I sent a long email response to your questions and it went direct to your name. I’ll try to copy or send the answers again thru the forum.
Rand
te:
Jeffeb3 LR3 Beta Crew Member
March 21
Rand:
Where do you enter these M500 codes?
Do you use Repetier host? You can send them from that. And you can see the results in the console.
Does Ryan have the exact file we used years ago that he could link
There have been dozens, if not hundreds of versions. Why do you want to use the older files?
I would use the most current version if you think it will work with a 4 year old build? I don’t understand the software enough to know if significant changes have been made. My old system was working and I just want to change as little as possible until I get it running again.
Print not coming on, movements odd and a different size ratio than called out.
Well, we need to focus on them one at a time, describe them in detail and see if we can solve them. I have forgotten all about the older firmware. So I would rather you start with something new. But I don’t honestly even know what your machine does. You keep saying print. Do you have an extruder installed on it? The new firmware is only for CNC.
My machine is a 3d printer with the MPC standard extruder and firmware .
Aren’t all 3d printers CNC controlled by G code instructions? What is the new firmware that’s only for CNC?
The Repetier program is performing very odd. Could I have a problem of interference from the cables, boards power supply?
When I load a file thru Repetier it slices okay, sometimes the temp appears on the screen , other times it doesn’t, I use the preheat pla 200 degrees, it shows on the reprap screen but not on the computer. The heated bed has stopped working
And I turn it off to try and print. Previously the bed would heat up to 50 degrees and then when met the extruder would come on and go to the preset temperature. When both parameters were met the print operation would start.
This worked for years and hundreds of parts. Then the extruder stopped working so I replaced the whole hot end. The thermistor reads 100 ohms and the heater works with 12 volts. The bed thermistor measured 58 ohms and this heater also works when given 12vts. The 4 pin connector on the Rambo has 5vt on both sets of pins. That’s why I suspect the Arduino.
Odd how? All those things can be broken. But it is more likely there is a simple reason for all of this.
The first step getting RH to work is to just connect it and check that the console is printing useful info. You can paste the console here and we can look at it. If you don’t see anything, try sending M115, which asks for the version information.
I need to be able to send G codes and to see the console results to make decisions. When I try to send code it comes back with an error message.
The emails don’t go through. They go to a robot, who ignores them.
Nothing about the builds had changed significantly. You might have a 5/16" threaded rod install of the leadscrew.
But when we changed to a new way of setting up the firmware, we switched to support the more common configurations. MP3DP printers were more common. So we stopped updating the config for the MPCNC with an extruder.
So the newer versions aren’t configured for a printer, and the MPCNC motion system.
That is sort of reaching a dead end on the firmware. We don’t have the older firmware source anymore. You could configure the new source for your machine, but you would have to learn a bit first.
The rest of the symptoms seem to fall into two categories.
- The heater/temperature is not reliable. My first guess is that the thermistor isn’t the same as the one before, so it is detecting a problem when it tries to heat.
- The machine isn’t getting constant connections to Repetier host. Make sure you haven’t installed Repetier server. Try a different USB cable.
Jeff,
If I wanted to change to MP 3DP firmware how do
I upload that version? I think it’s on GitHub but what parts do I load and is it Zipped? Do I select “code” and load that file?
I get a 100ohm reading on my thermistor and the extruder works. I have tried several cables shielded and normal with no change. I have another MPCNC I want to set up for a laser, should I just buy a new motherboard, preflashed, so
I won’t have the same problems?
I’ll check the M503 codes when I get back to the shop.
Rand
That doesn’t tell you much. There are quite a few thermistors that have the same resistance at 20C. The real difference is at 200C.
The MP3DP v2 looks like this:
The firmware is at MarlinBuilder releases. There is a V13DP_Ramps_MK8 zip there. It has a precompiled hex file and another zip with the source code.
If you want to flash that code as is, you can flash the hex file with xloader.
If you need to make any changes, you will need to change the source code and compile it using platformio.
My guess is that this firmware is pretty close to the newer version of your old firmware. But 1) the accelerations and speeds are way to high for the heavier gantry of an MPCNC. And 2) It is still configured for the mk8 extruder. So you will probably get the same min temp error if you have the wrong thermistor.
You can adjust 1) without changing the source code. You can set max speed and accelerations with gcode.
Jeff,
I have the standard MPCNC with conduit rails and the hot end just like your pictures show. The thermistor is the same one I used four years ago. The MP3 is very different. What can I do to replace the firmware with a version that will work with an older unit. I don’t want to reinvent the wheel but just get back to the point where things are stable and we can analyze one thing at a time. Should I reflash a new Arduino with whatever firmware you suggest?
Rand