issues with hotend temerature

[Barrisen]

Hi,
im having some issues with the hotend temperature stability like in the attached photo.
I have tried changing the thermistor but it made no differance.
it has been working about 500hrs before this.
What could be the issue?

 

[Barrisen]

Is seems to get worse the loger it is running.

 

[Oliver1975]

Have you pid tuned your heater=extruder?

 

[Barrisen]

Yes, have tried to retune the extruder a few times

 

[majic79]

What hotend? Heater cartridge issue?

 

[WorthDoing]

When temp "jumps" suddenly, in other words faster than physics would allow, focus on wiring and/or crimps. Having said that, your jumps aren't that large compared with others I've seen.

Hope that helps you narrow it down!

 

[Barrisen]

I found the issue, one of the cables for the thermistor on the x carriage had started to break. Thanks for the assistance!