huge problem. I've got smoke.

I've just put a ramps 1.4 with mega to replace my melzi.
Plugged in everything according to the wiki. Turned it on and smoke came straight away. I immediately knocked off the power.
I have no idea where the smoke came from and it was working great with my melzi. I'm now left without a printer (really don't wanna take it all apart again.) Pics of my stuff below. Only thing new is the orange cable from power supply. It's 1mm thick 2 core wire
Any ideas?

Scratch that. The pics from my phone are too large for the forum...

and now nothing. the power supply still has a green light but im getting nothing from the board or screen or anything,

could you post your pic to imgur and link the album here? 1mm thick flex core is asking for trouble, at least 1.5mm to 2.0mm (I think) is recommended which is 16awg at least

I looked for the size on the internet and forum and the size they said was 1mm... do you think ive blown it?

if it produced smokes means there's something shorted in the board

How would I figure this out? im new to all this and smoke is definatly new to me.

Check the solder joints for cold solder there, I also not very good in electronic stuffs, still learning

Cold solder? ill google haha

im so annoyed with myself im not sure it even works anymore

I "cold solder joint" is basically a solder connection that looks like it's making contact but isn't. It's basically a manufacturing defect.

From the description, I don't see how a cold solder joint would cause a short/smoke. Sounds to me either something is connected incorrectly/backward, or something is touching something that it shouldn't be.

Edited 1 time(s). Last edit at 08/19/2015 05:44PM by markts.

Do a visual check where the smoke came from. First check the chips and transistor, use your nose to detect burned electronics. If it's an easy to replace component and you've got basic soldering skills you could consider replacing it. If not, replace the board.

Check all voltages before connecting a psu using a voltage meter/dvm

I'd disconnect everything from the arduino and ramps board. First check the arduino if its still working by programming the firmware. Firmware can get erased or damaged if there's electrostatic high voltage, or other high voltages on the mcu.
If it doesn't program at all, replace the arduino.

Then connect the bare ramps witout anything attached, not even power. If that doesn't produce smoke, attach the external power supply. Use a mains hub with switch, don't use a plug as a switch. Very quickly turn it on and off. Check and feel if anything is running hot. if its running hot, replace the power supply with a different make/model/manufacturer. Some may have parasitic voltages and leakage because of a bad design. This could put AC on a DC output or cause a voltage difference between pc and switching psu.

Keep adding the least power hungry component one at a time and test it.

Edited 1 time(s). Last edit at 08/19/2015 05:57PM by imqqmi.

Magic smoke means something burned, probably somewhere in the RAMPS/Arduino stack. The most common error is to reverse the polarity of the +12V/GND from the PSU to the RAMPS, and that obviously results in smoke and damage to the RAMPS.

Depending on your skills in Electronics DIY, you may want to try to repair the RAMPS board or simply buy a new one. At current prices (~$8) I would suggest buying a new one. Then post pictures of your wiring here in this forum before applying power again...

Ok guys, quick update.

I've plugged the mega into the USB and it is powering on.
I then plugged the ramps into it, plugged in the USB and got a flashing LED with + next to it, which im assuming is good.

I then plugged the LCD screen in just powered by USB and got a bright screen with nothing on. I read online that the LCD needs more power than the USB can handle so I plugged in ONLY the power supply to the outside part of the mega (closest to the edge) and got nothing. no LEDs or anything.
I then swapped the power supply connectors over to the inner half of the power supply and got nothing.

The only time I am getting anything is from the USB connection.

The power supply light is green and there has been no change to it since it has been running my earlier incarnation of the printer (Melzi 2.0)

I have not had any chance to install any firmware on the board and I am unsure if it comes with any pre-installed.

So.... any ideas?

Edited 1 time(s). Last edit at 08/20/2015 08:03AM by muntahunta.

I've tried to power the RAMPS 1.4 board with the power supply with no arduino attached and nothing.

Any tips on what to do?

Buy a new RAMPS.
[www.amazon.com]

wouldnt the LCD not work if the RAMPS was broken?

Also, I know I wired things correctly last time as I triple checked the wiring against the wiki, so I'd prefer not to fry another one if I could find out what I did wrong.

is it definatly 100% broken?

Check here:

[forums.reprap.org]

though I don't see a solution from the last post. It would seem to me the connection from the power supply to the RAMPS is plugged in backward. That's just a wild guess though, but would explain badness when it's plugged in (but ok on US.

just read all of that and I have checked the "chip" next to the power input on the mega and it is indeed fried... however I am certain that I have my wiring correct. and also, wouldnt the ramps still work by itself?

What do i need? a new ramps? a new mega? both? a wiring guide that isnt going to blow up yet another part?

Quote
muntahunta
just read all of that and I have checked the "chip" next to the power input on the mega and it is indeed fried... however I am certain that I have my wiring correct. and also, wouldnt the ramps still work by itself?

What do i need? a new ramps? a new mega? both? a wiring guide that isnt going to blow up yet another part?

I wish I could tell you. I know nothing about the Melzi board, but it looks like the end stop connectors are two pin, as opposed to the Ramps? I went to look at that after watching this guy's video.

[www.youtube.com]

Have you tested the Mega as he describes?

I tried this before posting here.
He says that to test using the lcd (giving a white screen) that the USB power isn't enough, which is the reason i tried to connect the power, nothing happens when connecting the power.

with just USB I get the same white screen he gets, but that could be due to lack of power from USB in comparison to the PSU. So I cant use his testing method unless I have the power supply to work with, but it seems to not be working at all.

Quote
muntahunta
I tried this before posting here.
He says that to test using the lcd (giving a white screen) that the USB power isn't enough, which is the reason i tried to connect the power, nothing happens when connecting the power.

with just USB I get the same white screen he gets, but that could be due to lack of power from USB in comparison to the PSU. So I cant use his testing method unless I have the power supply to work with, but it seems to not be working at all.

Well, then you are using his testing method. Do you own a multimeter to check the power supply output? Maybe a 12v light bulb?

i dont own a multimeter, but since i plan on expanding my amount of printers to 5+ eventually, it may be a good tool to have.
as for a 12v lightbulb.... im not a lightbulb expert in any way, but im from the UK and im sure bulbs here are rated in watts. why, do you have an idea? (idea, lightbulb, ding.... ill leave now)

Quote
muntahunta
i dont own a multimeter, but since i plan on expanding my amount of printers to 5+ eventually, it may be a good tool to have.
as for a 12v lightbulb.... im not a lightbulb expert in any way, but im from the UK and im sure bulbs here are rated in watts. why, do you have an idea? (idea, lightbulb, ding.... ill leave now)

I'm sure you can pick up a multimeter for very cheap, and it will definitely be something you're glad to have every time you reach for it. I didn't know you were in the UK so I don't know for sure, but I was thinking an automotive light (tail light, etc) in the US operates at 12v so you can use that to test for output from the power supply.

The power supply is fine and working but I think you may have possibly solved the problem... I checked the power supply and its a 12v 15A.... Obviously it needs 16A, but surely this wouldnt give much problem if there is literally NOTHING plugged in other than the RAMPS?

Quote
muntahunta
The power supply is fine and working but I think you may have possibly solved the problem... I checked the power supply and its a 12v 15A.... Obviously it needs 16A, but surely this wouldnt give much problem if there is literally NOTHING plugged in other than the RAMPS?

No, that doesn't matter at all until you start running motors and heating the bed (which suck up the juice).


Are you saying it's working because the power supply LED is coming on? I suppose that's a good enough indication as any, though it'd be nice to verify the voltage. It could be a failure mode of the (blown) regulator such that you get nothing from the screen when powered by an external 12v, but it lights up when connecting by USB.

The only bright spot is the other person in the thread above replaced the Mega and it worked.

Well, The power supply was used to power my other board and it worked fine (apart from 0 USB connection) running 20 hours in a day.
The LED light is coming on and ill check tommorow if it still runs the other board (im expecting a USB ISP programmer tommorow for my old board to try and flash the bootloader).
To my knowledge the power supply is still working.
I will try and get a multimeter asap.
The only thing that i can think of (and i know very little about electronics and boards) is that i've screwed it all up somehow and I have no idea why so I will probably end up doing it again.

There are two sources of 5V logic supply on the arduino and ramps combo. 1st is usb, and the other is the 5V voltage regulator which you have described as "fried".
This 5V powers all the logic supplies on the ramps - LCD, stepper driver, endstops..
For the 5V voltage regulator to work, it needs a 12V input which can also come from two sources:
1) From your psu via D1 on ramps; and
2) From the 12V input jack on the mega board.

For the above 2 sources, since your voltage regulator is done for, then they wont be of any use.

Your correct that the 5V from usb isnt enough to power your lcd, however, it should be enough to know if your mega board can still function. This will dictate what you will need to replace
1) remove first your lcd and stepper drivers. This is to ensure that all usb power can be given to the mega board.
2) Connect your mega board to your pc's usb and try if repetier host can still connect to your mega board via usb. If it wasn't flashed with a firmware yet, you can try to use arduino ide to flash your firmware. This is just to verify if your pc can still communicate with the mega.
2a) If it can connect: disconnect it, plug out the usb, plug in 1 of your stepper driver, plug-in your usb again then check if it can still connect. This is to determine if any of your stepper driver were destroyed during the magic smoke event.
2b) If it cannot connect, then im afraid you have to replace your mega board.

If all drivers seems fine during 2a, then you might only need to replace the 5V voltage regulator chip. That depends on whether your capable of replacing it.

In my opinion, if you have the budget, better replace the mega and ramps board unless your quite confident that nothing else was affected aside from the regulator.

BTW, the regulator cannot be destroyed due to inverted input voltage only - inverted endstop connection/wiring can cause it to fail too.

Edited 1 time(s). Last edit at 08/21/2015 12:02AM by wderoxas.

Pretty good guide wderoxas,
I wouldn´t say the Mega-board is useless without 5V regulator. No need to replace it.
Just cut or solder off the D1 diode from the Ramps board and get a separate 5V supply ( eg. RC-UBEC ) and connect it anywhere on the Ramps, where 5V was meant to be ( servo or endstop +/- pins )

Much easier to solder a two pin connector to the UBEC-cable, than the solderjob necessary to replace the onboard regulator.
-Olaf