I3 V2 build help please

I am just finishing up my first build and cannot find anything that tells me where to plug in the fan for the extruder. Can anyone please provide guidance?

Thank you

Apparently have bigger problems. Display works but when selection made (such as move axis) nothing happens. Also when connecting usb into laptop, laptop will shutoff if printer is plugged in. I have checked all wiring and connections. Could this be a bad board? If so what should I replace it with.

Thank you

I had the Computer shutoff problem, I had to make sure the 3D Printer if off when I plug in the USB cable or risk burning up the computer.
It has to do with a different voltage potential between the two devices, and this voltage difference can burn up the computer or just burn up the USB ports...

Then I went to a Raspberry Pi always connected running Octoprint now I use the network to connect to my 3D Printers.

What 3D Printer controller are you using?

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Computer Programmer / Electronics Technician

First please pardon the ignorance. I am completely new to this "hobby" and am only somewhat computer literate. I will ask questions and provide answers that may may most shake their heads.

I believe the "controller" I am using is Arduino.

The printer kit I have put together is this one: REPRAPGURU DIY RepRap Prusa I3 V2
[www.amazon.com]

No mods made as of yet. When first assembled I could move x,y,z without issues, extruder would not move. I was trying to change the direction of the motors to make sure it "homed" correctly. After that the screen got very bright (could see white blocks only) when plugged into 110, I turned down contrast. It is now fine when connected to usb but still brighter when connected to 110 only. At that point the display no longer will move the motors. When I connect to usb and 110 at same time, laptop shuts down. I am thinking there is excess voltage somehow going through usb. I have checked every connection multiple times, think I must have shorted the board?

If you unplugged the motor connection while power was still on, you may have destroyed 1 or more stepper drivers,
remove drivers from the ramps board and see if it now works with 110 and usb connected.

Edited 1 time(s). Last edit at 04/07/2020 11:51AM by obewan.

removed all stepper drivers, still crashes cpu as soon as connected. Thank you for the suggestion though.

Try a USB data cable = no power connections.
The laptop and the printer are supplying power to their sockets. If you have a cable with the power wires inverted you short the sockets out and the laptop gives up first. Also there are different voltages for USB 1, 2, and 3. So the best option is to use data only. I can't remember which pins but there is only 2 that it needs.
Chinese USB cables are often unclear on their wiring.
Extruder fan is wired directly to the printer 12v power so its on all the time. So the wires go in the same connector as the 12v from the PSU. The print cooling fan is the one controlled by the board.

Thank you for the detailed response MCcarman. I crossed my fingers and connected printer to my desktop computer instead of laptop and all works fine. I have now used 1 spool of filament and having a little fun "building" different items.

Thank you and stay safe!

???

Edited 3 time(s). Last edit at 04/22/2020 08:51PM by Roberts_Clif.

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Computer Programmer / Electronics Technician

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???

And that took 3 edits!. Time for a beer I think. Or maybe you already had one. Stay well folks.

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MCcarman

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???

And that took 3 edits!. Time for a beer I think. Or maybe you already had one. Stay well folks.

When you wrote " I can't remember which pins but there is only 2 that it needs." do you really mean you connect ONLY these two signals wire, not V+ and 0, GND ?

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"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)

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MCcarman

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???

And that took 3 edits!. Time for a beer I think. Or maybe you already had one. Stay well folks.

I had written a large post, then decided not to post as it sounded - "How should I say this - Oh! It just sounded like it should not be posted no matter what was done to fix it"
As you cannot delete your own posts you are stuck putting something in as a space filler.

Thus I left ???

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Computer Programmer / Electronics Technician

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I had written a large post, then decided not to post as it sounded - "How should I say this - Oh! It just sounded like it should not be posted no matter what was done to fix it"

Ive done that.
As usual you share wise words.

MKSA. - Yes power and gnd are only to power electronics. Such as NON separately powered USB hubs, Inline data converters or even micro computers.
Power and gnd are the 2 outside pins.
Note that phone CHARGER cables some times ONLY have +V and earth. Data cables don't have the +V.

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MCcarman
MKSA. - Yes power and gnd are only to power electronics. Such as NON separately powered USB hubs, Inline data converters or even micro computers.
Power and gnd are the 2 outside pins.
Note that phone CHARGER cables some times ONLY have +V and earth. Data cables don't have the +V.

OK, Then I can tell you that not to connect the GND/0V IS STUPID and a way to potentially blow the USB port !

YOU JUST NEED TO CUT THE V+ !!!!! NEVER CUT THE GND/0V

Most probably if it didn't work with the laptop but Ok with the workstation it is because GND/0V was connected via the Main GND (most laptop power supply don't use the GND) !
Not the best way to connect signal ground either !

And BTW, USB here are 5V ! It is the last one, the C where the voltage can be different, negotiated for fast charging.

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"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)

Its not just USB C that can have different power options look at usb quick charge v3

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Dust
Its not just USB C that can have different power options look at usb quick charge v3

Does fast charge applies HERE to a 3D Printer connected to PC ????? Sorry for not listing ALL the standards about it.

MCcarman wrote about different USB voltage that could cause the issue discussed HERE. This is wrong !

ANYWAY, the key issue is THE DISCONNECTED GND/0V, with just D+ and D- connected !

In addition to blowing stuff, these chinese cheap power supplies can be DANGEROUS if the ground, frame etc are not properly wired.

This is the reason why I posted. People blowing stuff is funny but I can't pass on potentially life threatening issues.

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"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)