R2X Extruder fans not working

[ne...@roguesteel.com]

Hello all, hoping for a little help. The extruder fans on my Replicator 2X have stopped working - first the right fan started running slow, then stopped, a day or so later the left fan stopped. I ordered replacement fans from Makerbot, after two weeks of my order 'waiting to be packed', or ordered replacements elsewhere, plugged them in, but they don't work either. The connections all seem good, I know the fans aren't over tightened, so it's something else. In researching on this forum it sounds like it could be the FET? but I don't know what that is or how to fix it. Any suggestions would be appreciated.

Thanks,

Neil

[Scott Booker]

When the right fan on one of my R2X's failed it managed to pop the FET on the MightyBoard.  The MB was replaced by MBI under warranty.

Are you still under warranty... or perhaps have MakerCare for your system?

[Dan Newman]

The fans are likely fine. The issue is far more likely to be the FETs
dying on the motherboard. Known problem with the Rep 2 and Rep 2X.
However, it's a little odd that they would both give out. Usually it's
an isolated event with just one FET dying.

Dan

[Dan Newman]

And, as Scott points out, if a fan did indeed die it can take out the FET
controlling it. If you are good with a soldering iron, the FETs aren't
hard to replace -- I've done it on a Rep 2. But ideally, MBI would replace
the motherboard under warranty. Now, again it would be odd both fans
dying. But they likely came out of the same bin during assembly and maybe
MBI received a bad batch of fans and you got two of them....

Dan

[ne...@roguesteel.com]

Thanks guys. I am not under warranty, the machine is a little over a year
old now. And yes it seems odd that both fans went so I wondered if anyone
else had thoughts. If I could replace the FETs I'm sure that would be a
much better option financially than replacing the board. Anyone have any
tips/instructions for that?

[Ryan Carlyle]

Have you tried new fans yet? Just trying to rule out the obvious...

[Jetguy]

Look for the part that let the magic smoke out (smoke is put into the chips at the factory and if the seal breaks and it leaks out, they stop working).

I've circled the MOSFETs in question in red. Specifically, Q11 and Q9 control the extruder fans, Q7 controls the main blower duct on a Rep-2

I found the specifics here:

Dan Newman posted in the Tips and Tricks group in reference to a user with a 2X obviously a Rev G or H board https://groups.google.com/d/msg/3dprintertipstricksreviews/Vgq2z2_x1zc/9PfZqflsbBIJ

"The MOSFET they use for the cooling fan is a 2N7002K which is good for 60V but
only 0.3 A. So make sure that the two fans combined use do not exceed that
current rating @ 24V. 

[Jetguy]

Sorry, picture attached in quotes below the text. I hate it when it does that.

[Scott Booker]

I recognize the thumbprint on the USB connector housing....

;)

[Jetguy]

Sorry for the lift of the picture. I have no idea when I downloaded that, but it was the only picture I ever had of a Rep-2 board.

[Scott Booker]

No worries at all.  I could care less and if it can be used to help some folk, freely distribute.

But that thumbprint unlocks ApplePay on my iPhone.....   exposing the $.38 that I have i my account.  ;)

[ne...@roguesteel.com]

Thanks everyone for all the great information. (especially about the factory installed smoke! that's just the kind of thing you're not going to learn elsewhere!)

Seriously though, the picture helps alot. There is no visual indication that either of the FET's have blown, is that normal? and before I attempt to change them is there anything else I should check that could be the cause? As I said and the wires and connections seem to be good. Lastly, where can I find the replacement FET's? I'm determined to get this machine running again and I appreciate all the help.

Neil

On Friday, October 24, 2014 10:26:03 AM UTC-5, ne...@roguesteel.com wrote:

[Dan Newman]

> Seriously though, the picture helps alot. There is no visual indication
> that either of the FET's have blown, is that normal?

Yes. When those FETs die, it's with a whimper not a roar.

> and before I attempt
> to change them is there anything else I should check that could be the
> cause?

Fans themselves. Corrupt EEPROM with a on temperature which is no longer 50C.
As to the latter, you can look at the settings via the machine's onboard
parameters. I think but am not positive that MakerWare will show them.
RepG will if you have Sailfish installed. They are listed under the extruder
tabs.

> As I said and the wires and connections seem to be good. Lastly,
> where can I find the replacement FET's?

See the Digikey part number I sent you via private e-mail. You would
order them from digikey.com using that number.

Dan

[ne...@roguesteel.com]

I just wanted to thank you all for all your help - the makerbot is repaired and printing away!

Neil

On Friday, October 24, 2014 10:26:03 AM UTC-5, ne...@roguesteel.com wrote:

[Joe Smith]

What is the digikey part number for the FET? I have to repair the same thing on my rep 2....thanks guys!

[Jetguy]

2N7002K

[Joe Smith]

I see there are 25 different part numbers when I search for 2N7002K on digikey website. Does it matter which one I use? 

[Dan Newman]

On 28/10/2014, 6:34 PM, Joe Smith wrote:
> I see there are 25 different part numbers when I search for 2N7002K on
> digikey website. Does it matter which one I use?

Digikey 2N7002KWCT-ND. (The ones I normally get are out of stock right now.)

Dan

[Joe Smith]

Thank you!!

[mihai cotlet]

So, Neil it sounds like you fixed your problem.  I have the same thing going on with a Replicator 2X.  My left fan is not working.  Tried a new fan, no go.  Checked continuity on the wire, it's good.  Checked connections they are OK.

Did you end up removing the FET's and re-soldering new ones?  Please let me know.

My Replicator 2x is close to 2 years old, so it's out of warranty.  It is the one I use here at work, so it's not actually mine...

Thank you,

Mihai.

On Friday, October 24, 2014 11:26:03 AM UTC-4, ne...@roguesteel.com wrote: