A fix for Ultimaker 2 heated bed not working

[Rm7 1]

Hello,

We have 2 UM2 and one bed has stopped working gradually, the other one has started showing precisely 20C lower and then today stopped heating always showing 46C at 26C room.

We'll try the wiring today but do you think this in the picture is the temperature sensor and where can we order a new one to resolder?

[gr5 2,173]

It's probably not the sensor itself but in the wiring.  It should be about 108 ohms at room temperature.  Ususally you just have to tighten down a screw or resolder that terminal block (just reflow the solder).  The part is a PT100 which is a standard part and you can order one from anywhere.  All PT100s have the exact same temperature/resistance curve so any brand is fine - they come in all kinds of smt sizes.  Or you can also just get a whole new bed from Ultimaker support.

Edited August 1, 2015 by Guest

[Rm7 1]

All PT100s have the exact same temperature/resistance curve so any brand is fine - they come in all kinds of smt sizes.  Or you can also just get a whole new bed from Ultimaker support.

 

But are we correct thinking that the part we are measuring in the picture is the PT100?

The part is giving us megaohms, as well as the terminals so logically this is the PT100, right?

I've picked this one:

http://lt.farnell.com/ist-innovative-sensor-technology/p0k1-0805-2p-b/sensor-pt100-0805-class-b-0-04/dp/1266934

Edited August 1, 2015 by Guest

[gr5 2,173]

0805? Is that the right dimension? Or is it an 0603? I don't know. That part appears to be fine. I hope you know how to solder smt parts.

[Rm7 1]

We've resoldered the sensor it's very accurate now and the printer works great! Thanks!

[solid-print-3d 30]

Symptom --> Stuck at heating build platform when starting print

Fix--> Clean socket, cut and resolder wire

[Mizzo 2]

Hello everyone, since the UM2 and the original+ shares the same heated bed & electronics i though i could share my personnel experience with heated bed problems. Mine stopped working while printing at 100°C (for ABS) which had caused lifting problem to my raspberry pi 2 case :(.

I waited for the print to finish and tried to set bed temp manually, no error message or anything just the ulticontroller continuously indicating room temp, the nozzle heat up just fine so i knew that this problem was related to the heated bed wiring, i dissembled the bed to get access to the connectors. First i set the bed temp to 100 and checked the voltage with the help of a multimeter via the 2 thick grey wires yet to my surprise the reading was pretty normal around 24.3 V but after a close inspection of the connector doc i noticed that the soldering of one of pins had melted down and voilà !! that was the problem. So i just had to do some soldering and while there i reinforced the other 3 just in case. I hope this could help you out. PEACE 8)

[ultiarjan 1,223]

And if you have an older UM2, the 4 wires of the cable can be soldered causing a loose connection over time (happened to me 2 weeks ago) in that case just cut of the soldered part and reconnect.

[Mizzo 2]

Hey guys !!!

Well im facing a new problem ( see previous post ) :( when i power on my UMO+ the ulticontroller is not indicating room temp for the heated bed " 90/0° ". When i try setting the heated bed manually to 100° it start heating up but to no surprise stooped when it reach 100/100 (when in reality heated just 10° from the indicated 90).

I tried reinstalling default firmware (cura 15.04) but still the same. I wonder if the temp sensor is busted.

Any ideas ...i would really appreciate your help. PEACE

[Mizzo 2]

Lazy me all i had to do is to go back and read gr5 replies. I disassembled the bed ,unplug and re tightened the sensor wires then i checked the sensor resistance again and now it's working normally ( i think ).

Moral of today !!! always check the forum throughout before posting your problems.

[boogo123 9]

Ok, just like many others here i also ran into the problem with the heated bed.

Here is THE way to fix this problem, it works !

The problem is on the board itself and is caused by the thin ( to thin ) lines that go to the contacts for the temp sensor.

I took out my heated bed to inspect the soldering, looked fine but still the bed caused problems, the temp goes crazy, runs up to 150 degrees + and than you get the error.

this is how to solve it permanently..

remove the screws on the block where the 4 wires are attached. You need a soldering iron on 385 degrees max.

remove the block and clean the contacts on the board and the contacts on the block.

Than put new soldering on the contacts on the left ( the ones that heat up the bed )

solder the block back but only the 2 contacts on the left.

Now take 2 thin electrical wired and solder them on them on the block on the right ( for the temp sensor )

In the picture you see the brown wire goes to the sensor on top, the red one goes to the sensor below.

solder the 2 wires there and it works like a charm again.

Here below is a picture of the solution, i think that everybody who has worked on the heated bed can recognize this and sees how the solution works.

I found out that the lines on the board for the temp sensor are very very tiny, you can not resolder them, to little.

but with these 2 bypasses, it works perfectly again

Good luck

Marco

[wnygren 0]

My heated bead stopped working after 5 months. Upon taking it apart I noticed that the clamp that holds the heater cable to the aluminum plate is too large and doesn't completely stop the cable from moving/flexing - so the cable or the solder joints or screw connections  are fatigued or loosened and finally fail. I wrapped the cable with tape to increase its dia and this seems to have fixed the problem.

[catohagen 41]

 

I just did this, works perfectly, thank you