Printer Head Fan Not working

[aelric23 2]

Hello. I have an Ultimaker Original Plus. A while back, my printer head fan was not functioning so I ordered two new replacements just in case. Plugged both in, and neither worked. Made sure to get the exact 24VDC replacements. The interesting thing about the fans is that they will run if you move the prop yourself, but it will not provide adequate cooling at the speed it maintains. It also will not initiate the fan to spin. I checked the connector on the board, and the output is correct when the printer is turned on (19.4V without the fan connected). I have been reading on the forums that it may be the Darlington Transistor which is burnt out, but I have no idea on how to check a transistor to see if it is functioning correctly (I'm an ME not an EE). Can anyone help?

Edited June 10, 2016 by Guest

[neotko 1,417]

Umo+ bc817 transistor for me it's broken when:

- Fan stays full power at any setting

- Fan at 255 goes slower than at 100

Best way to check it for me it's to plug a led light 24v (I use the ones that ultimaker uses on um2).

Other test it's just to plug the fan on the led pwm and turn the lights on. To do so install amedee custom firmware builder that will add a 'led' controller on your ulticontroller. This way you can check if the fan works.

Btw it's very important to check the +/- before pluging a led/fan to a um2.1.x board because if you plug them inverted the transistor dies almost instantly.

Search on google bc817 neotko transistor ultimaker for many post that I did about how I fix my transistor 6-7 times already.

Ofc one think. I remember that there was a post in french where @electromu was talking with someone about how to test if the transistor was or not dead. But I can't remember where was that post since it was on french. @electromu do you remember that post?

[electromu 364]

Hi,

@neotko this is this post https://ultimaker.com/en/community/19803-probleme-ventilo-et-solution?page=last but Zizon have deleted the thread and now pictures are out.

this is the original picture.

@aelric23 do you have a multimeter ?

[aelric23 2]

Hi,

@neotko  this is this post https://ultimaker.com/en/community/19803-probleme-ventilo-et-solution?page=last     but Zizon have deleted the thread and now pictures are out.

this is the original picture.

@aelric23   do you have a multimeter ?

 

Yes, I do. I was able to read the voltage off of the pin. Probably missed if the polarity was opposite or not.

[neotko 1,417]

If everything fails and the transistor it's really dead you can replace the transistor with a bc817-24 or edit pins.h of Marlin building you own firmware and reroute the led so it works controlling the fans. Search my posts "bc817 neotko ultimaker" it's all there (or almost).

[electromu 364]

 

Hi,

@neotko  this is this post https://ultimaker.com/en/community/19803-probleme-ventilo-et-solution?page=last     but Zizon have deleted the thread and now pictures are out.

this is the original picture.

@aelric23   do you have a multimeter ?

 

Yes, I do. I was able to read the voltage off of the pin. Probably missed if the polarity was opposite or not.

 

Ok,

take your multimeter and chose the diode tester.  symbol like this: diode symbol

Disconnect the power supplie and switch ON the mainboard.  (it's important to drain capacitors)   all tests are power off

fisrt test:     red probe on pin 1 (see previouly picture of the transistor)   and black probe on pin 2    you must measure 1,1Volts

second test: red probe on pin 1 and black probe on pin 3  you must measure 1,1Volts

third test: red probe on pin 2 and black probe on pin 3  you must measure 0,7Volts

You can compare measures with the other transistor (T2)

give us your test result.

bye

Edited June 11, 2016 by Guest

[aelric23 2]

Ok, results are as follows:

Test 1: T1 = 1.980, T2 = 1.982

Test 2: T1 = 1.980, T2 = 1.553

Test 3: T1 = 0.002, T2 = 0.818

Thanks.

[electromu 364]

RIP T1 :/

One jonction of the transistor T1 is KO.

You be able to change it ? with hot air gun or with a little soldering iron.

or use the method exposed by @neotko to reroute fan to LED driver.

[neotko 1,417]

If you find someone with soldering skills (if you don't) the transistor bc817-24 it's sooo cheap. I payed 50€ the first time to a professional to do it. But the 2nd/3rd-7th time I did it after learning with a friend.

Here's some photos of the process I used the last time.

[aelric23 2]

Yeah, kind of guessed T1 was dead after reading all of the voltages on both Transistors. I have pretty decent soldering skills, so I can probably replace the transistor myself. Might also use that kapton tape method you had going there neotko. Smart idea if you don't want to accidentally poke another component. I'll have to buy a finer soldering tip. and looking at other people's experiences, maybe order 10 or so of those transistors as backups. Thanks for the help everyone.

[aelric23 2]

Finally fixed it!! Working 100%. Replacing the T1 transistor wasn't too difficult, but I was able to do it in a short amount of time. Didn't need the Kapton tape, but I recommend to anyone trying it themselves, to heating up the bad T1 and pulling it right off the board. Also, lay down some flux as it helps make the soldered joints when you finish nice and clean.

[nitrotech 1]

Are these acceptable replacement transistors?

http://www.digikey.ca/product-detail/en/nxp-usa-inc/BC817-25,215/568-1630-1-ND/763457

[electromu 364]

http://www.digikey.ca/product-detail/en/nxp-usa-inc/BC817-25,215/568-1630-1-ND/763457

Yes this is good.