Heather bed cannot preheat(also temps from bed rising really slow)

What is the problem?

i get an error while preheating my bed(
Error: Heating failed, system stopped! Heater_ID: bed - echo:Heating Failed
)

What did you already try to solve it?

Rewired everything and bought a new motherboard and made sure the power supply was adequate

Have you tried running in safe mode?

Yes

Did running in safe mode solve the problem?

No

attention! Important

PS: i don't got the SD card problem because i don't have a SD card slot

Datasheet:
Velleman K8200 with ramps 1.4.2 motherboard

Add:
I also noticed when measuring the V during preheating that the V fluctuates between 1 and 4.65 V, should that be the case?(power supply seems to be working fine)

Hello @Julien_Burgaz !

When you opened this thread there was a querry for the Systeminfo Bundle

Could you please attach it to your next post.

BTW:
Do you run the bed with the original 15V?

Hey Ewald thx for your reply

System info Bundle:
octoprint-systeminfo-20221113163429.zip (258.5 KB)

Iam a bit new so I just put the cables from the bed into the ports on the board so i don't know if it runs on 15v

Have you deleted the logs after that issue?
The octoprint.log is just a sequence of 17 milliseconds. with no information about your issue.

The K8200 is usually powered by a 15V power brick. Due to the weak heat bed performance, I modified my K8200 to run the bed on 24V.