[Help] 5V and Vcc shorcircuit

Hello,

Checking the 5V and Vcc pins (shown in the picture attached I have short circuited them (well, I really don't know which of two of the three near pins were connected) but I saw a puff of smoke and now the pins no output voltage. Also the LCD screen turned white (see the other image attached). The printer preheats the nozzle and the bed, move in all axis when I command it with the LCD click encoder but it doesn't read the SD card and the USB port seems also to be broken because OctoPrint can't connect with the board to print "wirelessly".
Anyone knows what I have damaged? I hope it's just a diode that I can manually exchange...



Help is appreciated, thanks

The pins are connected like this:

Pin VCC connects to Arduino pin 5V (between pin 3.3 and pin GND) This pin supplies power to the RAMPS 1.4 5 volt bus.
Pin 5V only connects to the middle pins in the servo section, beside the reset button on the RAMPS 1.4
Pin PS-ON connects to Arduino PWM pin 12

Shorting Pin VCC to Pin 5V will not (in itself) damage anything. This is commonly done with a jumper to use the Arduino 5 volt regulator as a power source for the servos.
Shorting Pin VCC to Pin PS-ON might damage the Arduino if pin 12 is 'on'

It is also possible that the 5 volt regulator is damaged on the Arduino. This can be tested by disconnecting the RAMPS board and testing the Ardiuno pins for voltage between GND and 5V.

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-David

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Hello David,

Thanks for the help.

I may then short-circuited VCC pin with PS-ON one.
I have tested the 5V regulator and there is 5V voltage between the big leg and one of the smaller three ones (is that correct? how can I test it is working fine completely?). I have also tested in Arduino the voltage between GND pin and 5V pin and it outputs correctly 5V. Finally, I have tested RAMPS and between VCC pin and 5V pin there is no voltage but there it is between 5V pin and PS-ON pin... I'm unsure if this is correct because before I damaged somehow the board/s I tested 5V voltage between 5V pin and VCC pin (as far as I remember... may be I'm wrong).

Any idea?

Your measurements between the Arduino 5V and GND pins should be the same as measuring between the RAMPS 1.4 pins 5V and one of the GND pins in the servo section (the four pins nearest the edge of the board)

The measurement between the RAMPS 1.4 pins 5V and PS-ON will depend on the state of the Arduino pin 12. If the software is instructing the pin high you will read zero volts, and if the software is instructing the pin low you will read 5 volts.

From what you posted, it seems that the 5 volt bus (and the Arduino) is probably okay...

---

-David

Find me online at:
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Check out my FolgerTech Prusa i3 (plexi) at MindRealm.net

Thanks MindRealm,

You are right, the servos GND with 5V pin are giving me an output of 5V... so that the voltage regulator should be fine and the problem is in another place... any other suggestion? remember: LCD screen turned white, it doesn't recognize when the SD card is inserted (so that can't read the files inside it) and I can't connect to the Arduino through the USB and my computer or Octoprint (Raspberry Pi)...

In case you suggest to change a board, do you think I should change both (Arduino and RAMPS) or just one? which one?

Thanks!

We'll start with some basics:

Remove the RAMPS 1.4 board from the Arduino and try connecting to the Arduino alone with the USB.

1 - Do any of the LEDs come on?
2 - Does the computer recognize the USB connection?

---

-David

Find me online at:
Thingiverse
Instructables.com
LinkedIn
Facebook

Check out my FolgerTech Prusa i3 (plexi) at MindRealm.net