Temperature problems

[Wink-IT]

Slowly I despair with the A10M. After everything is calibrated fine now the extruder makes problems problems with heating up.
The heating process is getting slower and slower and more often it quits with an error message "heating failed..."
First it came at temperatures over 230°C but now I can't reach 200°C already.
I tried to autotune the pid for the hotend and the bed, but it does not make a difference.
The tension of the hotend is 23,9v and the hotend has a resistance of 15 ohms.
What is wrong? The printer is just two weeks old!!
And what does the support say about that? Where can I get in contact with them?
I wrote an email but they just answered that I should contact them via whatsapp or facebook.

[_kaktus_]

Hi.


Check that all connections are good. I mean the heating circuit of the hot end.

[William]

It should be these reason:
1.The PSU part
If the PSU has an issue of the output(More than 50% load)
You can use another PSU for a test
2.The motherboard mosfet overheating
You can check its temp and then try to add the heat sink for it.
3.The PID is incorrect.
You can try to use the "M303 E0 S200 C5".

[Wink-IT]

Its getting more and more strange.
I measured the power supply and can't find anything wrong.
The same to the voltage and resistance of the hotend.
Always when heating up to 220°C from 180°C to 200°C it will get more and more slow and quits with an error message.

But when autotuning the pid it will heat up to 250°C without problems!
So how can you explain that?

[_kaktus_]

Hi.


In that case, I think it's a software problem. See what William wrote in point 3.

[Wink-IT]

I did pid autotune several times up to 240°C.
And while autotune runs the hotend heats up to the desired temperature without problems.
But after that I always have the same problem. The heat process is taking very long time and quits with an error message.
What I already did/tried:

1. Measured resitance of hotend and thermistor. both are ok.
2. Measured the power supply. same here, everything looks fine.
2. Checked cables and plugs. Everything ok.
3. Did pid autotune several times. Without any improvement as described above.
4. Uploaded actual firmware.
5. Wrote to support and described my problems. They will send a new hotend. But I'm not realy shure that it will be the cause of my problem.

And now I have no idea!

[Wink-IT]

I think I got it.
Measuring under load while heating up bed and nozzle revealed significant voltage fluctuations (12V to 23V).
I think the power suplly is causing the problems.

Now I measured the voltage at the other printer (A10) under workload (nozzle 250°C, bed 85°C).
The voltage looks stable but it is at 10V.
Is this normal behavior?

[_kaktus_]

Hi.


Bravo, in my opinion, you found the source of the problem.
So replace the power supply.

[William]

The voltage should be 24V when the PSU is under load status.
Your PSU seems has an issue of the output.
Try to contact the sales to send you the new PSU.

[Wink-IT]

I measured the voltage at the other printer (A10) under workload while printing.
Its working without problems but the same there. The voltage is going down to 12V.
That would mean both PSU of the printers are defective after only 2 weeks.