What have I fried?

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Pum
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What have I fried?

Post by Pum » Wed Aug 01, 2018 1:51 pm

Hi Makergear Tech Support community – may I beg a little advice please?
I was trying to fix a friends faulty M2. The extruder feed was jammed. Unfortunately, another problem was that the wires to the small fan on the front of the extruder feed assembly were previously broken off and hanging free, and they accidentally touched the metal filament feed roller whilst it was all turned on (I was heating up the blocked hotend in order to be able to clear it.) I think that shorted something, and now the whole thing doesn't turn on :(

I will check at the fuses on the electronics board when I next get a chance, but does anyone know whether it's likely to just be a blown fuse or have I fried the electronics board or something else?

Thanx in advance, Pum.

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ednisley
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Re: What have I fried?

Post by ednisley » Wed Aug 01, 2018 3:51 pm

Pum wrote:
Wed Aug 01, 2018 1:51 pm
a blown fuse or have I fried the electronics board or something else?
The schematics don't match the quick-and-easy documentation, neither of which may match your board, so check all the fuses.

The schematic shows the red fan wire connects directly to the +24 V supply through fuse F3, the little one at the power input connector. That's the most likely victim.

The doc says check fuse F2, the little one beside the power connector, for the same conditions, even though it also shows only the motors connected to F2. Just a typo, perhaps; could happen to anyone.

Fuse F4, the big one in the corner, carries the platform heater current and should be unaffected. Of course, F4 is the only cheap and easily purchased automotive-style fuse on the board.

Start with F3, pull each one, and, if it's not obviously kaput, measure the resistance: a good fuse will have nearly 0 ohm resistance, a blown fuse will be open = infinite resistance.

You need a multimeter to measure the resistance, but you should have one anyway ... [grin]

Pum
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Re: What have I fried?

Post by Pum » Wed Aug 01, 2018 4:05 pm

Thanx for the quick reply and yes, I do have a multi-meter, and shall try to use it carefully ;)

Pum
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Re: What have I fried?

Post by Pum » Thu Aug 02, 2018 9:32 pm

I checked and fuse F3 is indeed blown. Order new ones. Hopefully will get them in time to try this weekend. Thanx.

Pum
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Re: What have I fried?

Post by Pum » Tue Aug 07, 2018 9:34 am

Fuses arrived and fitted. Everything working except extruder drive motor. Testing indicates the Rambo is not sending a signal to motor – swapped Z-axis and extruder connectors on Rambo; extruder works, Z-axis doesn't. I guess that means replacement Rambo needed?

The extruder nozzle and filament drive were badly blocked. Is this problem likely to have been caused by shorting out the fan wires, or by trying to extrude when it is completely blocked?

Thanx, Pum, London, UK

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ednisley
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Re: What have I fried?

Post by ednisley » Tue Aug 07, 2018 1:56 pm

Pum wrote:
Tue Aug 07, 2018 9:34 am
Testing indicates the Rambo is not sending a signal to motor
The board has two extruder drivers, so you can (probably) use the (presumably) undamaged driver.

This requires tweaking the Marlin firmware source code to use the other driver, recompiling it, then reloading the Arduino, but it's been done. Search the forums for other threads on swapping extruders.

Edit: Come to think of it, you can plug the extruder cable into the E1 socket, tell S3D to use Extruder 1, and it should Just Work. Certainly worth trying ... [grin]
trying to extrude when it is completely blocked
Steppers are constant-power devices which can run "stalled" forever without harm, although the hardware gives off enough staccato noise to scare the daylights out of you.

Flailing wires kill electronics with gleeful abandon, so ...

Pum
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Re: What have I fried?

Post by Pum » Thu Aug 09, 2018 11:40 am

ednisley wrote:
Tue Aug 07, 2018 1:56 pm
Come to think of it, you can plug the extruder cable into the E1 socket, tell S3D to use Extruder 1, and it should Just Work. Certainly worth trying ... [grin]
Yeah, I tried that with no success. Maybe it's not that simple, or maybe both are fried :-/

I'll try swapping to E1 on my working M2 to see if it should work. Thanx.

Pum
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Re: What have I fried?

Post by Pum » Mon Aug 13, 2018 1:24 pm

Well I searched through the forums for a ready made firmware that swaps to use extruder 1, and couldn't find anything.
I picked up a few tips, and had a look at the code – it looks like it specifically says to use 1 extruder and would need changing to use ext1 instead of ext0, but I do not feel confident figuring that out; I have never coded this kind of thing before.
I wonder if I put the M2 dual extruder firmware on, that presumably enables both extruders, and just use ext1 from S3D.
Or perhaps Makergear techies have a firmware for single extruder on ext1 – they may well have an in house unit that ext0 broke on and they hacked to use ext1.

jk42
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Re: What have I fried?

Post by jk42 » Mon Aug 13, 2018 4:33 pm

We would be happy to assist you via our support center.
Please contact us a support@makergear.com. We may be able to get some firmware
together to test your board.
~Jason from MakerGear

Pum
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Re: What have I fried?

Post by Pum » Wed Aug 15, 2018 11:19 am

Thank-you, I will do.

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