One thing you could check perhaps is when everything is disconnected (all connections except 15 V and USB cable) take off all 4 motor boards (before switching on power) switch on power and check the voltage output of your regulator again. It could be one of these boards which is causing a shortage. Then you know at least that the issue is in either the mainboard or in one of the motor drive modules, which makes a huge difference in price buying a new item.
might be the case…
anyway, you can source the naked main board from italy for around 40-50 euros.
They’re all soldered onto the main board with like 16 joints each…
Is velleman not likely to offer a replacement for this board?
Sorry, you’re right. They came lose pretty easy.
And holy crap the regulator output turned up to 4,99 with all of them off. So i guess i’ll just try the modules on by one and see which ones are shortcircuited.
I’m not exactly savvy with electrical stuff so i got some great feels here making progress. Thanks for the help.
Do you know where i could order the modules separately?
I guess i must have shortcircuited these myself when i meassured the motor outputs. I never actually trimmed them but i guess i did it with the multimeter pins.
Ask velleman for a replacement driver.
You can source them from a varitety of supplyers.
The type is Pololu A4988
http://www.pololu.com/product/1182
After removing all the drivers and not finding a faulty one, i put them all in again, and the voltage output rose to 4,99. So i don’t know what was the problem here. Was one of them poorly socketed somehow?
I can connect with repetier host now but i get a temperature problem (bed temperature 700+).
Also, can you tell me if this is normal: LED 5 and LED 6 are now constantly lit up with the USB connected but with no powersupply on. When i connect the power supply they go out. Until i connect with repetier host, then they start flashing regularly (~once per second)
LED 5 and 6 are the usb connection leds.
so that should be ok.
That indicates a short circuit in the thermistor wiring.
The thermisor resistance is 80k in room temperature. The cables soldered onto the therm-holes in the heated bed is also 80k. But when i try to meassure on the therm2 female, i can’t even get a reading. Its not zero resistance, it’s very big resistance. Multimeter set to 2M shows it as 1. ohm (too big to meassure).
Doesn’t look like a shortcut. Did i mess up the cable joints under the heat shrink tubing?
Set your meter for 200K
The resistance should be around 100K at room temp.
When it is unplugged the software should show 0C under manual control.
Meter set for 200k.
I meassure on both ends of the thermistor, it reads 80.
I meassure on the cables i soldered into the holes marked “therm” on the heated bed, it also reads 80.
The software shows 0C when it is unplugged and 738C when plugged in.
The extruder is 21,8C when plugged in.
Do you have it unplugged when you measured it?
Hi Stefan3d,
Have you checked the resistance at the terminal which goes into your board ?
Do you have 80 kohm also there ?
You could have some mismatch in the flatcable wiring if not.
Guzzler does have a very good point.
You should check the wiring.
Yes, it’s unplugged when i measure it.
[quote=“Guzzler”]Hi Stefan3d,
Have you checked the resistance at the terminal which goes into your board ?
Do you have 80 kohm also there ?
You could have some mismatch in the flatcable wiring if not.[/quote]
Hi, yes, i tried measuring the terminal which goes into the therm2 slot on the board, but i cant get a reading here. No matter what OHM range i set my meter for i always measure 1. in this terminal. But i dont have a mismatch with the cables going in. I’ve double checked both the instructions and the colors on both ends of the flatcable. It looks right.
So it looks like one of your 2 wires is not end to end connected to your thermistor.
You should have 80 there as well. Check resistance from terminalwires to thermistor.
On both wires it should be either 0 or 80, something else on one of them indicates that that wire is disconnected
I redid the soldering on the wires and i got the heated bed working. Thanks for the help.
Glad to hear it.
Enjoy.
strange.
That sounds like an open circuit in the wiring.
Although, when having an open circuit the temp readings in repetier should normally drop, not rise