Thanks Torgeir, will try your suggestion.
Best regards
Still no joy with this. All above checked and new PT100 fitted.
So:
New Board
New Heated Bed
New PT100
New printer?
Hi Silures,
Well, what happened when you swapped the connectors Temp1 and Temp3?
If the failure swapped from Temp3 to Temp1, you have a faulty wiring for bed temperature! So, If this is true, it should be very simple to confirm by using an ohm meter. Note; if there is an intermittent failure in this wiring, the failure may come on an go off as the bed is riced or lowered. This due to an intermittent contact when the wiring is moving due to bed height level changes.
If nothing changed, you have some failure in the firmware (telling there is a bed temp error) or that there is a real hardware failure on your main PCB.
The statement of this check will tell us what part of the system we'll find the error / the failure.
So what happened?
Thanks.
Torgeir.
Hi thanks again,
When I swap Temp sensors 1 and 3 the error message changes to "Temp Sensor"
My feeling is that the error is in the wiring somewhere from the bed to the board. But I can't seem to see any connection problem and there is a 20v at the heated bed.
The error is consistent and doesnt change with moving bed around up down or the cable to the bed etc.
Perhaps trying a new cable to the bed might help? Cant seem to source one online but will look again. Thank you again
Hi Silures,
This is kind of strange as you said you measure 20 V at the heat bed..
Cause the whole printing program normally stop and there should not be any voltage present at the terminal point were the two grey wires are connected.
Well, unless there is some other firmware allowing this (?) -but doubt in this matter.
If you use the resistance function of your multi meter, does it show close to 0 ohm when the measuring pins are shorted?
Further, across the two terminal screws (use the pins directly on the two screw for the temp sensor), here the resistance should be around (108-110*) ohm in room temperature? (*)Edited
The problem with the PT100 sensor have often been located to the terminal contact point. Those two black wires are kind of tiny, so strip the insulation twice as long as needed then twist each of the wires a litte and fold it back so the length of bare wire is correct. The idea of this is to obtain more of area into the clamping and make the conduction better at this point.
Same can actually be done for the two power wires, yes in this case -only on the board with screw terminals.
Thanks.
Torgeir.
Edited by GuestYou are measuring different pairs... mixing heater with sensor won't do any good.
The pt100 cables are near the small pt100 sensor (left) the black colored cables.
Btw is that an original heated bed? The logo looks weird? Just wondering...
Edited by GuestOk, thanks so the PT100 cables measure 4.75 volts. The bed I purchased from eBay listed as UM replacement bed. Your right I don't think it is original ;(.
I have the old bed though and If I get this to work I may swap it back.
So this is like a 3 minute fix for me. Do you have any electrical engineer friends?
Anyway you don't want to measure the voltage on the PT100. You want to measure the resistance. And measure it from the other end of the cable (at the board underneath) and measure it with the cable removed. It should be about 110 ohms. Plus or minus 10 ohms. When at room temp.
That error would indicate it is either 0 ohms or shorted. Probably 0 ohms.
That error is almost always a bad connection right at the board. Right where you are measuring. So I wouldn't even bother measureing anything. I would just resolder the two connections there under the screws. And also loosen, remove and reinsert the wires and retighten. The thinner wires. The thicker 2 go to the heater which is not your problem. The thinner two go to the sensor.
Hi Silures,
As I've had to go to Ireland, there was no way to answer in here.. Well, you see the power of this site, lots of help in here.
Hi again..
Too bad that internet is not very good right here. Lost 90 percent of the mail.. So see you sometime next week.
Torgeir.
Was thinking why does the error still occur when the bed sensor and power on the board is all removed?
Is there a way to run the printer without the heated bed?
Could do this until l get a solution.
Edited by Guest1) First of all you should not measure the temp sensor WHILE IT IS CONNECTED TO PCB. The electronics in the PCB will most likely mess up the measurement even if the power is off. If the power is on it will 100% guarantee measure wrong resistance.
2) Yes you can print without heated bed. Put blue tape on it. Clean the blue tape with alcohol using a tissue to remove the slippery waxy surface (you won't feel a huge difference - just do it - it makes a huge difference letting parts stick better). And then when you start the print immediately go to the TUNE menu and set the temp to 0C. Or you can set the temp to 0C in the material settings for the current material you have loaded e.g. PLA.
Hi Silures,
When you are using your multi meter as shown, you are measuring between one power wire for the heat bed and one sensor wire from the PT100 temp sensor.
The voltage you see here is normal, but have no meaning for our use..
Actually there should be no voltage present to the heat bed as your PT100 temp sensor is not working correctly! When measuring the heat bed power, you have to measure between the two gray wires. When measuring the PT100 sensor you measure between the two black wires.
Your printer should never been powered when doing this measuring as we do not measure voltage, but resistance.
So, disconnect the bed temp sensor when measuring resistance (as gr5 adviced), (no power on the printer) and measure on your bed between the two terminal points where the two black wires are connected. If you find the resistance to be between (108-112) ohm your PT100 is probably OK. Next point to measure is at the connector (still unconnected to the main PCB). As you already have swapped temp 1 and temp 3, we know that your bed temp sensor is out of tolerance. Carry out the above test, using the setting on your multi meter as shown on the added picture. Then measure at the connector using needle or wire links from arduino kits etc.
Here is the first picture of your multi meter indicating the correct setting for measuring resistance.
Here is a picture of how to measure a PT100 temp sensor at the connector.
Zoom in to see the two other places might be used..
Note: When measuring resistance, connect red and black pin together and check that the resistance is 0 ohm or very close to zero! When those to pin is disconnected from each other the reading is normally OL (open line).
Good luck.
Thanks.
Torgeir.
Well, my now nearly 6-years old UM2 came to the point of being totally non-functional due to the error mentioned above.
it took me several rounds of disassembling, checking, soldering and desperation.
All that until I finally found this thread and got on the right track - PT100 resistance. It wasn't there. Knowing now where the problem is, it was fixed in 5 minutes of yet another soldering round and resulting resistance verification.
All in all, many thanks to @gr5, @Torgeir and @Silures for the guidance!
P.S. Ordered replacement board nevertheless.
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Torgeir 280
Hi Silures,
Welcome in here.
This error indicate that there is an error with the PT100 as the resistance is out of tolerance. And this is the only errors that immediately end the printing program..
The right thing to do here is to measure the PT100 resistance from the connector located at the main PCB "TEMP3". Remove this connector and measure the resistance on this connector (should be around 108 ohm at room temperature (22 deg C)).
You could also swap the two connectors TEMP1 and TEMP3 to see the failure will swap from "heat bed sensor" to "temp sensor". This wiring from the hear bed to the PCB should last very long, but in some cases they break or suffer for intermittent contact at the heat bed connector.
Go to this place to find more info about the system, also download the UM2 manual to find more information if needed.
https://ultimaker.com/en/resources/160-error-messages
Thanks.
Torgeir.
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