Printer not working due to mainboard failure?

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morganfree
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Printer not working due to mainboard failure?

Post by morganfree » Fri Mar 09, 2018 3:58 am

Hello to all!
I was installing a new case for the Viki 1 screen, so I had to remove all wiring and rewire.

After doing that, I turned on the printer and I noticed the screen was not showing information at all: Just ON, but didn't seem to work.
I checked its wiring, at it was OK... so apparently the problem wasn't there.
I connected the printer via USB to the computer to check if the communication with each other was ok and if I could control something: it connects but nothing works. There's no temperature information. If I turn on the heaters, S3D will show them ON, but they're not heating and continues nor showing temperature. Any other command via G-code would not respond neither.

SO I went back to the board and noticed that I've missplaced the FAN0 connector, using half of the FAN0 board plug and half HEAT1 plug... It took (-) from HEAT1 and (+) from FAN0... I repositioned the connector to the right position and turned ON... everything's the same.
2018-03-08_232907.png

Finally, I remove the Viki and reckeked with S3D, same result...
WhatsApp Image 2018-03-08 at 23.36.03.jpeg
The board as it is now, ON. There's a red light in front of the heaters connectors... Is that Ok?
So now my question is: Did I burn my board!!!??? :shock: :shock: :shock:

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insta
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Re: Printer not working due to mainboard failure?

Post by insta » Fri Mar 09, 2018 4:27 am

You *may* have blown a MOSFET, but it's more likely you blew one of the little beige fuses near the power inputs.

If your LCD isn't working, swap cables A & B.
Custom 3D printing for you or your business -- quote [at] pingring.org

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morganfree
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Re: Printer not working due to mainboard failure?

Post by morganfree » Fri Mar 09, 2018 4:38 am

Thanks Insta.

I'll check the fuses.
insta wrote:If your LCD isn't working, swap cables A & B.
Just a question... What would be the reason for switching A-B wiring for the LCD? I mean, I didn't modify anything, just rewire the same board the same way... Just to understand why would I need to do that?

Thanks!

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morganfree
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Re: Printer not working due to mainboard failure?

Post by morganfree » Fri Mar 09, 2018 12:09 pm

Good morning.
Just to update my post.
I measured the 5 mosfet outputs voltage, just FAN1 is measuring 23,6v. The others are not measuring at all.
The fuses; the three of them are at least not broken (continuity check).

What else can I check? Or should I consider my board was fried? hahaha I'll have to take it to a technician, if it's that the issue, until I receive a new one...
2018-03-09_075229.png

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ednisley
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Re: Printer not working due to mainboard failure?

Post by ednisley » Fri Mar 09, 2018 2:29 pm

morganfree wrote:just FAN1 is measuring 23,6v. The others are not measuring at all
Each connector has one wire to the +24 V supply and one wire to the MOSFET, with the MOSFET acting as a switch. If you measure across the terminals, you'll see (about) 0 V when the MOSFET should be off and (about) 24 V when it's on.

[Edit: got it backwards. Needs a schematic. Mumble.]

If you measure from each terminal to circuit common at any of the the - terminals on the power input connectors, you'll see a constant 24 V on one terminal, because it's coming directly from the power supply. The other terminal will measure 24 V when the MOSFET is off and 0 V when it's on.

Which confuses the daylights out of everybody the first few times around the block.

Assuming you're measuring across the connector terminals, FAN1 is off and all the others are on.

Measure the voltages from each screw terminal to circuit common: if you don't see 24 V on either connector, then a fuse has blown or the power input connectors have a problem.
Last edited by ednisley on Sat Mar 10, 2018 1:55 am, edited 1 time in total.

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Tim
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Re: Printer not working due to mainboard failure?

Post by Tim » Fri Mar 09, 2018 4:18 pm

morganfree wrote: SO I went back to the board and noticed that I've missplaced the FAN0 connector, using half of the FAN0 board plug and half HEAT1 plug... It took (-) from HEAT1 and (+) from FAN0...

So now my question is: Did I burn my board!!!???
To answer this specific question: I had a fan and a power supply handy, so I looked at what happens when you connect reverse polarity across one of these fans. The answer is: not much. The fan draws a bit more current (0.25A instead of 0.15A, for the fan I was testing), and doesn't run. The MOSFETs only switch in the ground and the positive supplies are all shared, as Ed indicated. So at worst, you reverse-biased your fan, and that should not have done anything to your board.

Note that the motors are run from motor drivers, not power MOSFETs. If everything is not responding, and your fuses are okay (which appears to be the case; you're getting a red light where the MOSFET is on, and from the picture it looks like the green power indicator light for the CPU power supply is on), then it's time to check the firmware. Check that you can run simple commands. Like type in "M115" and see if it responds with firmware information.

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morganfree
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Re: Printer not working due to mainboard failure?

Post by morganfree » Fri Mar 09, 2018 11:16 pm

Well, I'm really lost about what happened... But I'm really happy because everything went back to normal! :D :D :D

Since I had disconnected the LCD (Viki1) I reloaded the original firmware (following Tim advice), just to check if something would respond through S3D. For my surprise, everything worked! Temperature readings, axis movements, heating and so on. W/O the LCD the machine seemed to work normally.

Next step was to reconnect the LCD (I did it following insta advice of switching A-B wiring), and double check if the problem was an LCD related. I've reloaded the firmware for the LCD... and again, for my surprise, everything worked back again! This time through the screen and S3D.

At that time I was using a different USB to connect the printer to the computer (Following a MG support advice, too)... but when I used the normal USB (the one that I always use) it all worked too...

As you can see, I've applied all of your solutions!!! hahahahh

Anyway, I can't really say what really happened. I rewire the same way I was doing yesterday (or at least I think that). Yesterday nothing worked and I freaked out! Today, the sun rises differently or some planet alignment helped me too... hahaha

Really, I might say I was doing something wrong yesterday (for sure) and I didn't even notice...

Anyway, thanks to all of you for your help! Thanks to you I went back to double check everything and apparently I was doing something wrong...
Other interesting thing I've discovered through this post was how to measure voltage at the connectors (thanks ednisley), since I was doing that the wrong way.

Best regards all of you! Enjoy your WE!

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