First…many thanks for your patience, I do appreciate it.
The first test was to connect to Heater2 Gate and ground. With Heatbed off 1.1v and on 1.1v.
The second test was connected to Heater1 Gate and ground. With Heatbed off 1.1v and on 5v.
18.2 V at the gate?
Should be 5v max, as directly driven by the Microcontroller.
Are you sure you didn’t measure source (output pin of the mosfet) to ground?
And, why 18.2V? Do you power the controller with more than 15V?
Yes I measured the source. I was not quick enough to edit the post before you read it.
What we need to know is if the gate (control pin) is correctly driven by the microcontroller.
So we can tell if it’s the control circuit or the fet that’s damaged.
Ok so I connect one probe to pin 18 and where does the other probe go.
The other goes to ground.
So that you measure the 5V logic signal driving the gate of the mosfet.
Question again:
What voltage do you feed into the 15v connector?
Normally there can’t be more than 15V on the source of the Mosfets, as they are powered from the 15V main supply.
15v I assume. It’s the normal Velleman power pack. I will test it again, I might have misread the meter.
I have been a nervous wreck pocking and prodding about in the controller. The most dangerous thing I do these days is tie my shoe laces. I’m just glad you are about to hold my hand…
Completed the test. The reading was 1.1v with the heatbed on or off.
Just to make sure, on both heaters, or only on the non working?
If the latter, please crosscheck with the working one.
The reading was 1.1v with the extruder off, and 5.5v with the extruder on.
Ok, so there is a problem with the control voltage.
If it’s not the Software i fear your Atmega chip is damaged.
Before sending in the board for repair i would suggest you to reupload the firmware and afterwards
restore factory settings and save to EEprom via repetier, just to make sure it’s not an EEprom or firmware issue.
Ok, I was hoping it would be the Mosfet, an easier fix.
I will do as you suggest before sending it back. Do you have any idea of the turn around time.
Many thanks for patience and help, I have also learned a lot about the electronics of this machine.
I will keep you informed.
Tony
[quote=“Freff789”]Ok, I was hoping it would be the Mosfet, an easier fix.
I will do as you suggest before sending it back. Do you have any idea of the turn around time.
Many thanks for patience and help, I have also learned a lot about the electronics of this machine.
I will keep you informed.
Tony[/quote]
Can be that the mosfet is bad too, and thus killed the controller chip.
I hope it’s only a software issue.
For turnaround time of repairs contact Velleman directly, opening a support ticket on the website.
I’m not Velleman staff, so i can’t answer that.
Anyway, you’re welcome.
cheers,
Christian
[quote=“Battman540”][quote=“Battman540”]Update on my no additional electronics needed to add in a separate 24vdc power supply.
I have just completed printing THREE “build your own jet engine” projects (thingiverse.com/thing:392115) and the printer is working fine. This job was about 30 plus hours of printing which puts the life cycle test at around 70 hours total with no problems and the LED is still working fine.[/quote]
For those of you that are concerned about my method of adding in a heat bed power supply with no additional parts, I have an update. The controller board is still working perfectly and so is the LED.
I have now worn out the bearings on the X & Y belt and also the extruder (all replaced with quality sealed bearings) and everything is working fine.
I have lost count on the number of hours on my K8200 but it runs about 20-30 hours per week.[/quote]
Printer electronics are still working great with my NO PART 24V heatbed upgrade. I’m having issues with the linear bearings now that I’ve got so many hours on the printer.
Could someone please point me in the right direction… I’m after links were to buy in uk the stuff required to upgrade my heat bed as I cannot print abs at 50/60 degrees on k8200 I’m after all the stuff required for the 24v upgrade and were/how to connect/solder it in… I’ve checked the wiki but can’t make head nor tale of it… I need a wakthrough guide and were to buy the stuff from if that exists please… Thanks for any input luke
Hi, I want to improve my k8200 heatbed to 24v,
I´ve had a switching power supply 15v 4.5A - 24v 3.75A 90w max. output and power expander I got from: reprap.me. I have wired up everything as guided ( I guess),
but still it`s not working right.
Electricity goes power supply to power expander and then it goes to heatbed, and the control power from mainboard to power expander.
When I push the manual button heatbed on, mainboard light on heater2 is light up and Repetier shows temperature is rising very slow, only 2celsius in 5 minutes?
So what I miss ? Not enough ampers to power supply?
It was faulty power supply. Now I ordered a new one.
Maybe it helps…
What are the mods needed in firmware to get the 0/1 controling? And how to find the firmware?
What exactly do you mean?
I mean how to turn the analog heat bed controlling to binary 0 and 1 controlling?