Major issues on Ultimaker S3 Motherboard (bed continuoulsy heating, and hot electrical components)

[DoktorAce 0]

Hi,

 

I recenlty had majors issues with my ultimaker S3.

 

On the last print, the bed started to heat continuoulsy which led to very high temperature (way more than the set temperature) which led to a break of the glass bed and the burn of the glue on it (c.f. picture 1). After reboot, I realized that the bed was always heating even with temperature set to 0.

 

Picture 1.

 

I opened the printer to see what could be wrong with the motherboard and I discovered that some oil that was on the vertical rods dropped on the motherboard. The right vertical rod opening is located just above the motherboard. The result was that 2 diodes that are used in the regulation of the bed heating were grilled (c.f. picture 2).

 

Picture 2

 

I replaced diode 1 with a Zener 30V, and diode 2 with a 2A 200V rectifier diode. The result can be seen in picture 3 and 4.

 

Picture 3

Picture 4

 

Now the printer is back to normal behaviour. It does not heat if heating is not requiered and the regulation is good for all checked temperatures (from 50°C to 110°C).

However, the mofset (component 3 in picture 2) is really hot when the bed is around the set temperature. If heating is not activated the component is cold, is temperature is increasing to reach the set temperature the component is cold, but when the regulation is performed around the set temperature, the component gets really hot (maybe around 80°). I tried to rework the heat junction of the component (on the left) to improve the heat transfer but it does not help and the pcb is already getting hot which implies that the heat transfer is good.

 

So, my question is, is this nominal bahaviour that this component gets so hot ? On the component datasheet, I read that the component can reach 150°C.

 

Thank you for help.

 

[Dustin 137]

You should contact UltiMaker Support..... thats not normal.
https://support.ultimaker.com/s/contactsupport