Original UM does not extrude

[groumph 0]

Hello,

After a few happy months of printing, my UM has stopped extruding.

This is not a cold extrusion prevention, all test have been done >170°.

What I have checked so far:

Swapped Z and extruder stepper drivers and drivers are fine.

Swapped Z and extruder motors and extruder motor is fine.

What I don't understand:

It first happened when I put the UM on a cable. I set the UM on a table on which the power cable was running. The cable was between the motherboard's fan and the table.

Since then I have moved the fan by unscrewing the 4 screws a bit, and the UM worked fine for a few runs.

But now, it just will not extrude.

Did I damage something on the board? It there a sensor somewhere I can test? Can I test using ext #2 output?

Thank you in advance for your suggestions and help!

Yves

 

[gr5 2,069]

Swapped Z and extruder stepper drivers and drivers are fine.

Swapped Z and extruder motors and extruder motor is fine.

 

Sounds like the arduino got damaged somehow. Or maybe a bad solder joint between the arduino and the stepper driver. What country are you in? (please put that in your profile). Here in the USA you can get a new arduino for $20 including shipping. In other words, they are so cheap you might as well have an extra one or two sitting around.

 

[groumph 0]

Hello,

Thank you for your prompt reply.

I'm in Montreal, so I can source an arduino easily, but I think the bad solder is the best lead, because it would explain why by playing with the tightening strength it would go on and off (by bending ever so slightly the PCB).

So, how do I go about testing the solder joints?

If I cannot locate the faulty joint, is there a way to buy just the PCB without the arduino and the stepper drivers? €195 is a bit steep :(

I really appreciate your help!

Yves

 

[groumph 0]

Hello again,

I started visually inspecting the PCB, looks ok (but that might be because I don't know what I'm looking for).

I took advantage of the fact that it was taken out to pull out the arduino and reflash it with the latest version of cura (since I read the flashing might not be done properly with the arduino connected on the shield).

Yves

 

[gr5 2,069]

Were you careful to flash with UM1 firmware and not UM2 firmware? I think you have to select "machine" first.

 

[gr5 2,069]

by bending ever so slightly the PCB

 

Oh! Yes, cold solder joint. Get some reading glasses or a magnifying glass and get some very bright light. google "cold solder joint" and select "images". This will show you many examples of what one looks like. Each one you see you can fix by touching it to a soldering iron for a few seconds. Don't leave the iron on there for more than 20 seconds or so.

 

[groumph 0]

Hello...

... and thank you for your much appreciated advice and help.

Firmware - Yes, I selected UM1, no extruder update.

Cold solder joints - I googled it, and I am going to start looking for the culprit(s) on the PCB.

PCB - Looks ugly, all around the pins to the arduino it looks like it overheated and the servo connection has been used before: something was there then taken out. I wonder just how new the board was when it was shipped... I'd like to upload a photo, I just can't figure out how.

Yves

 

[gr5 2,069]

Solder has mixed in with it a gunky brown material called "flux". Flux helps the solder flow but once you are done soldering it is no longer needed. Some people wash the flux off with a powerful solvent such as freon (alcohol works I think). Flux looks VERY SIMILAR to heat damage. But it is not damage. If you touch it then it should feel sticky. It should clean off with powerful solvents (not water).

To post a picture you can upload anywhere on the internet such as imgur.com but if you insist on uploading here click "gallery" in the top left corner of this page, then click upload. Once your picture is uploaded, start a new post and click "my media" next to the smiley face icon. New users (under 3 posts? 5 posts?) can't upload to the gallery.

 

[gr5 2,069]

By the way, I looked it up and both alcohol or acetone works to remove flux. Even the best flux can cause corrosive damage to your circuit board over many years so it is best to clean it off although most electronics don't as most electronics aren't designed to last more than 5 years.

 

[IRobertI 516]

Isopropyl alcohol (called rubbing alcohol in the states I think) cleans up flux residue nicely. It's what I always use on my boards.

 

[groumph 0]

Hello all!

Thank you for your help, my UM works

I identified 2 solder points that looked suspicious and fixed them as per your instructions and VOILA !!!

I am not touching that board (cleaning the solders) now that it works but thank you for the I advice, I'll keep that in mind.

Again thank you!

A quick question, in desperation (and not wanting to spend €200 on a new board) I looked at alternatives and found the sainsmart 1.5.7 which sounds better than 1.5.6 (that's the novice speaking...) are they compatible?

Yves

 

[illuminarti 18]

Ooh, interesting. I didn't know anyone else was building and selling UM electronics. Not sure if that's entirely legit under the licensing terms of the design, although it is open source. The 1.5.6 and 1.5.7 versions of the UM electronics were pretty minor revisions that don't make much material difference to anything, as far as I know.

 

[gr5 2,069]

found the sainsmart 1.5.7

 

Wow. Wow. Yeah it looks compatible. Usually these types of boards need minor modification (swap a cable around or cut a trace) to work with Ultimaker but in this case it appears to be compatible (don't know for sure).

I hope they published their design and parts list and so on. If they didn't they may be in violation of the license.