Poor surface finish

i have an m200 with almost 5000hr of printing.
I had some issues with poor surface finish and missing material, together with random clickings form the extruder, so i went throught the throublesooting guide and realized that the extruder cable was gone.
After something like 150hrs of printing i found those defects… the gray print was the last and seems the worst.
I already tried to change the thermistor and the pcb, which i had as spares, but it seems like the issue is not fixed… Is the cable gone already?

other print.
between this and the gray one in the previous post i had other successful prints

Hey there. It is possible, however, make sure that your nozzle is clean first. When was the last time you replaced hotend? Also, make sure that heater&thermocouple is properly inserted in the hotend (as in this instruction: https://support.zortrax.com/thermocoupler-and-heater-replacement/). Do you have top cover v2 installed? We released it to extend extruder cables lifespan, so make sure that you have it.

Hi Marta,
the nozzle has been replaced and it has now something like 50hrs. The hot end has now 1700hrs, the first one lasted 2970hrs.
This is the 3rd calble i use, the first one lasted 2970hrs, the sencond 1500 hrs. My hardware is the v4.
I’ll check the thermocouples