Temperatur Problem M300 dual

[babelfish]

Hi there … my problems seem like:

Temperature problem

Over a year of printing with M200, prints have been coming out great and I am using the same materials mostly PLA+. Suddenly I cannot print at temperatures which I have been using so far (220 which is on a high end of recomended). The material loads without a problem, when I do 2nd load material it comes out perfect, continuous that is most likely because loading is set to higher temp. Once I go ‘print’ the model the material; gets stuck right away. I have experimented with temp and when set …

Just with our m300 dual.

Also there is no problem while loading the material…

I changed the whole (double) hotend, nozzles, i tested much and searched for the problem and now I can say that the temperatur at the hotted can’t be right.

So i tried to always increased the printing-temperature (external-setting) until the print worked.

Now I know I can’t print with the build-in filament-settings.
(tested with 3 Z-filament’s)

I have to take the external-Material-settings and raise the temperature for about 50°C.

example:
Z-PETG with 275°C
(real external) PLA with 250°C (instead 200-220 - eryone)
(no more positiv tests on my side till now)

Where I can measure, test or repair something?

Printer was delivered in Okt 2021 - the serial-number is linked to my email-address - the email-address is used by this forum-account. (if you can see that)
The new hotend(s) are delivered 2 or 3 weeks ago.
(problem is known about 1 month)

Thanks for your help

Update: 27.3.:
I found another hint:

When i start a print following temperature are shown:
Hotend A: 0°C
Hotend B: about 55°C
Bed: raising

While raising the temperatur on Hotend A the Hotend B get colder and colder (sometimes fluctuating) to about 22°C.

[TKAstudio]

I have never resolved this issue, instead I fine tuned temp for different materials now around 250. Besides that I had the same issue with the bed, always printing @ x2 temp = 60 not 30. Additionally, I measured temp with laser thermometer and it checks out, it matches the setting. I never discovered what is the underlying reason. My printer is getting old and I will be looking for something that can print much larger, I am also experimenting with UV printers which are pain but prints are so much better = I gave up on resolving this.