trying to get my kit setup (weird power issue)

Hello all,

My name is Steve. I decided to get a delta printer about a month ago and have been slowly assembling it since. I bought a he3d dlt-180 because of the cost and kind of regret that decision. I'm hoping someone can help.

I assembled everything and plugged it in last night and nothing was responsive, no leds, no motor buzzing, no display... nothing. Thought maybe the arduino needed the firmware (downloaded the kossel mini firmware) so I flashed that onto it. hooked it all back up with just the arduino, ramps board, and display board/cables. when powered via usb the display comes on just fine. but when trying with the power supply It's the same as before

https://www.youtube.com/watch?v=PIO4gJNfUW0

hopefully someone can help.


thanks,
Steve

only thing I can think of is that the power from the usb connects differently to the motherboard.
ie: you've got a wire crossed from the mains power supply somewhere.

My other thought is that both my printers (not deltas, so probably not relevant) run on 24v.

I'm also aware of the lack of support from he3d - so maybe the instructions (assuming you got any) could be wrong.

Unfortunately my electricity knowlege is sparse at best :-)
have a word with geoff he's built more than a few deltas.

Does the electronics stay on if you power it through USB and also turn on the 12V power supply? If so, can you get any motor or heater activity out of the printer that way? That would help prove whether RAMPS is getting 12V at all. I know of a few people who have had issues with the 12V connector scheme used on RAMPS, so that would be a possibility.

After that, one thing to look at would be the presence of diode D1 on the RAMPS board. The diode is underneath the X axis and Y axis stepper motor driver boards. If you have a multimeter capable of testing diodes, you could use it to test D1 to make sure it isn't open circuit.

RAMPS is installed on a MEGA2560 board, right? In the MEGA2560/RAMPS combo, diode D1 is used to pass 12V from the RAMPS 12V 5-amp input to the MEGA2560 board. The MEGA2560 has a voltage regulator that can use it to create 5V for use with the MEGA2560 electronics and the LCD. The MEGA2560 will automatically switch between using 5V from USB if it is there or the 5V from that regulator on the MEGA2560. If D1 isn't there, is open circuit, or is installed backwards, 12V won't be fed to the MEGA2560 board, and the MEGA2560 would only be able to be powered from USB, which is what you have.

As Curious Aardvark mentions, some printers run on 24V instead of 12V. The MEGA2560 board DC input can't handle 24V input. In that case D1 would be removed to prevent the 24V from being fed to the MEGA2560, and the MEGA2560 would have to be powered from USB or from some other dedicated 5V source. This is one reason why there might be RAMPS boards out there with diode D1 not installed.

If D1 checks out OK, you're likely into some diagnostic work with a multimeter to figure out what's going on.

So i checked the vin pin supposed to give power to the arduino. not getting any power. that explains why i'm seeing what i am. D1 is there and all of my soldering equipment is at work so i'll have to wait till tomorrow to desolder d1 and test it. I'm not getting power to either side though so likely that isn't my culprit. I've read a little about the duet system and how much nicer it seems to be. if i can't get the ramps board working I may try the duet route. thanks for the help. I really do appreciate it.

Have you been able to determine whether 12V is getting to anything else on the RAMPS board? The diode D1 possibility assumes it is. There are other possibilities if 12V isn't getting onto RAMPS. For example, a short in the 12V circuitry can cause the 5-amp polyfuse on RAMPS to open up as long as the short exists. There are two polyfuses - a 5-amp one for the electronics, motors and extruder heater, and an 11-amp one for the bed heater. The polyfuses are the large, postage-stamp like squares near the 12V inputs on RAMPS.

If you're not sure about the 12V and want to try something, one way forward would be to disconnect as much as you can from RAMPS, like the motors, the heaters, etc. I'd even consider removing the stepper motor driver boards. Leave the 12V power input connected. If the electronics powers up with things disconnected, you know the problem is in the stuff connected to RAMPS. If the electronics still won't power up with everything disconnected, and you know you have the polarity of the power supply connections right, you're down to an issue on RAMPS or the MEGA2560.

ok, so I checked the ramps board a little more. for some reason i'm getting 10v on 1 leg of the bed heater connector and 12 on the other? seems odd then again i haven't told the unit to heat the bed so perhaps that's not unusual. I disconnected absolutely everything and get the same result. Fuses are good. Checked the voltage at the stepper drivers when the 12v power is on and the .5 volts that it should be getting is there. once i'm at work tommorow i can get a schematic of the ramps board and begin checking it out in detail. I believe the ramps board is the culprit

Just to clarify - the polyfuses used on RAMPS will open up only for as long as an over-current condition is present. They will automatically reset back to being low resistance when over-current condition is removed.

OK, so I read that you can desolder d1 and just run the unit off of usb as well as the power supply. that's what I've decided to do for now as it is the quickest way of getting up and running. I'm having trouble now with repetier host and testing everything. no matter how I wire the stepper motors or what button I push, the hot end always moves down towards the print surface not towards the end stops. if I manually trigger one of the end stop switches it stops as it should but I just cannot figure out why its moving down instead of up.

First time visit on your forum, that was amazing and unique to another forum. And good comments on your post. Thanks for sharing.

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Originally Posted by hegel

OK, so I read that you can desolder d1 and just run the unit off of usb as well as the power supply. that's what I've decided to do for now as it is the quickest way of getting up and running. I'm having trouble now with repetier host and testing everything. no matter how I wire the stepper motors or what button I push, the hot end always moves down towards the print surface not towards the end stops. if I manually trigger one of the end stop switches it stops as it should but I just cannot figure out why its moving down instead of up.

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Hi

It's been a while, and the firmware may have changed. At one time, if an end stop was triggered, you could not move towards that end stop no matter what you told the printer to do. I suspect that is still how things are set up. I would check the wiring on the end stops and the firmware settings.

Bob