Z18 Extruder stepper motor problem -Julien- FABLAB ENIM

[Julien zins]

Hello,

 

I’m in charge of the FABLAB in a French Engineering School in Metz.

We have 3 MakerBot 3D printers (Z18, 5Gen and Replicator Mini)

I use Smart Extruder + with my printers

I’ve a problem with my Z18, after Error  50 « Heating Short » and replacement of Transistor

PBSS4041PZ(60 V, 5.7 A PNP low VCEsat BISS transistor)

http://uk.rs-online.com/web/p/bipolar-transistors/8015634/

 

Before :

After replacement :

 After replacement error 50 disapear and Extruder can heat to 215°C 

But T$the Z18 stepper motor of the Smart extruder don’t turn correctly…

The motor shaft seems to have small movements but does not turn and not pull the filament, there is no error on the screen of the Z18.

I tried with another extruder (Smart extruder and Smart extruder +) and the problem persists...

I’ve try to test the motor independantly and it’s seems to be OK

Probably a problem on the card ?

Do you have an idea ?

Do you know where I can find this card ?

My Z18 have 1,5 Year and warranty out of date, the company that sold me the machine went bankrupt ...

Thanks a lot

 Julien

[tramalot]

narly - red boxes at bottom

[Jetguy]

The MakerNOT (and no, that's an INTENTIONAL misspelling) 5th gen does NOT use discrete stepper drivers.
Instead they use a complex microprocessor and H-bridge to create a firmware based stepper driver.

A stepper motor is a 2 phase motor and requires that BOTH phases switch in a sequence (step table).
If one of the phases was damaged, then it will not rotate the motor.

So here's the problem, without schematics you have the impossible task of figuring out what failed.
In theory, it could be Q3, Q4, Q5, or Q6 but there is no guarantee that's the failure or the ONLY failure.
You also might pay attention to the silkscreen and note that STEP, DIRECTION, and ENABLE is listed, and it points to the bottom 3 holes of the 2x3 (6) pin connector location in the lower left corner of the picture as posted.
If you new the 12V source, you might be able to take an external stepper driver, connect step, dir, and enable pins and just drive the stepper motor from that driver.
I have no idea if that actually works, just pointing out the obvious of the silkscreen in front of us.

On Tuesday, September 6, 2016 at 3:27:31 PM UTC-4, Julien zins wrote:

[Jetguy]

The only source of that board is MakerBot or a MakerBot reseller, and unlikely that MakerBot just lists that part.

Again, you are at a point where you either reverse engineer that board by hand in front of you (because it's not open source and they are never going to release a schematic).
Some of that work has been done by myself and others at a high level, but not down to fully discrete components on that board.

You're almost better off buying a junked or refurbished MakerNot Mini, as that particular board is common between all 3 models. Going price on a refurb mini was as low as $500, in fact, a search showed as low as $399
http://www.ebay.com/sch/i.html?_nkw=makerbot+replicator

Unless a miracle happens and MakerNot feels extra generous on an out of country, out of warranty machine, I'm betting the control board costs more than buying a refurb machine.

[Ryan Carlyle]

Q6 looks kind of scorched to me from the photos.

Your motor symptoms suggest only one motor coil is getting switched properly. Q6 being damaged would probably do that.

[Robb Hunter]

I'm dealing with the exact same issue. I have found a source (I think) for all of my fried SMT components except for Q5, which looks a bit toasty on my board. 

Did you have any luck repairing the board or sourcing a replacement? 

-r