UM2 dead Power Supply

[clews 0]

Hi all!

A couple of days ago I had some problems with my power supply (PS). The PS was disconnected for a couple of hours, when I reconnected it, the blue led did not turn on. After disconnecting and reconnecting a couple of times it went on again. The PS stayed connected for a couple of days.

Yesterday, I tried to start the print but the heatbed did not manage to raise the temperature (display reported the "ambient temp" of about 20°C). I tried to manually increase temperatures via the advanced maintainance, the noozle heated up but not the bed (perhaps 1-4°C, but not sure).

I tried to turn the printer off and on again, no changes. When I disconnected the PS and reconnected it a couple of minutes later, and tried to turn the printer on, it went on for about a second and went of. The blue led of the PS went to half (or less) of its normal brightness. Since then the PS seams to be dead.

In the past few months, the PS made some hissing noise (which is frequent on switching power supplies) especially on load (heating the bed).

I submitted a ticket, but I hope to get some information sooner (as it seems that the support is a little behind schedule).

I suppose it is just a dead PS, but before replacing it, I would like to get shure that there is no short somewhere that would kill a new one...

What should I check ? I suppose the cable for the heatbed, the headbed itself (resistance). Anything else?

(I have some skills in electronics, but prefer to get some information before disassembling anything)

 

[gr5 2,270]

I had a power supply that I gave up on and then a week later it works fine. I bought a 3rd power supply and all 3 work but sometimes they need to rest a few days. Once they come on and the printer starts printing I've never had a problem. It's only when the printer is off. This is probably unrelated to your problem.

I also hear the very quiet "hissing" sometimes.

I doubt there is any kind of serious short on your machine. I think it would be a more consistent problem.

Contact support now because it may take a few weeks to get a new power supply if you are still in warranty. If you are no longer in warranty these power supplies are easy to find. But expensive.

I also once had problems with K1 relay where my bed was cold and servos wouldn't move but everything else worked fine. Here is a video talking a little bit about the problem and a solution. The final solution (with advice from a founder of UM) was to jumper K1 out as it isn't really used:

 

 

[clews 0]

Thank you for this fast answer... Indeed, the PS recovered after about 30 hours of pause, I think get a spare one to avoid further "waiting time"...

The heatbed still does not manage to raise temperature (sensor reports the ambient temperature around 20°C), but the servos are working (X, Y, Z and extruder). I've read some things about the connector which doesn't seems to be very reliable...

 

[gpb01 23]

You can get the UM2 Power Supply from Mouser (www.mouser.com) ... search, in their website, for Mouser No: 709-GS220A24-R7B

Guglielmo

 

[clews 0]

Okay, finally it really seems that the PS has a problem, after my test yesterday (was not printing anything, just tried to get the buildplate temperature up, which failed), this morning (I wanted to try a print with cold buildplate) the power supply led was off, the UM2 was switched off all night, put PS was connected...

I'm waiting for reply of the support right now, but I think I will definitely order a spare PS (thanks Guglielmo for the hint), I do not want to see my UM2 unusable for a couple of weeks...

(Even think of building an UM+ to have a spare machine ;-))

 

[clews 0]

Okay... PS works now (for some time). Did a quite well test print by setting the Bed-Temperature to 0. But on the second print I had a strange behaviour:

* When starting the print from SD (Bed temp set to 65°C) the UM2 restarted itself (lights going off, the normal startup)

* I tried again to start the print, this time it worked, but on printing the X-Motor did some strange loud noise and the head didn't move correctly. (Tested homing too, didn't work on X)

* I turned the UM2 off and on again, then tried to start the print again...

* Same symptom first, UM2 restarting itself

* After restart I didn't take the risk to start a print again but tried to home the head and it worked...

Sounds again like a weakness of the PS.

Next step: Should I try to disconnect the heatbed to see if I can limit load on the PS until I get a new one?

I'm still not convinced by the fact that this is only a PS issue. Ordered a new PS from a local supplier, should get it in the afternoon (if I manage to be at home) or tomorrow morning...

 

[gr5 2,270]

Should I try to disconnect the heatbed to see if I can limit load on the PS

 

Yes, but simply leave it set to 0C to "disconenct" it. Cover the glass in blue painters tape and re-level. Clean the blue tape with isopropyl alcohol (very important step or parts won't stick well). Now you can print PLA parts just fine until you get a "good" power supply.

Make sure you mark your power supply clearly so you don't get it confused with the new one when it arrives.

 

[clews 0]

Okay.. Got the new PS (wow, that was fast, well it's always good to know the right people in the right companies to get things quickly, though not always the cheapest solution)...

Tested it, same symptoms :shock:

UM2 resetting itself, not raising temperature... Now I physically disconnected the buildplate (removed the two thick cables and isolated them with a terminal strip), at least to be able to print some "preconfigured 65°C-Heatbed-SD-Card things" and to see if the self-reset comes up again...

But no luck... After a couples of minutes, the Ultimaker resetted again by itself, in the middle of the print this time... A problem with the controller?

Looks like this will be a longer pause for my UM2 (and I have some projects pending where I need 3d-printed parts quite urgently... :???: ).

 

[gr5 2,270]

1) Are you printing through USB or using the SD card?

2) Do you have a multimeter? Do you know how to use it? You should check the voltage of a few key parts. You want to monitor the 24V, 12V and 5V supplies when the problem occurs to see which supply is causing the problems because each one requires a different fix. I mean if 24V is fine but either 12V or 5V is not then it's definitely the white PCB.

ULTIMAKER 2 SCHEMATIC - click "raw":

https://github.com/Ultimaker/Ultimaker2/blob/master/1091_Main_board_v2.1.1_%28x1%29/Main%20Board%20V2.1.1.pdf

 

[clews 0]

1) Most of the time SD-Card. Right now I have a problem to recognize the printer on my MacBook via USB. I'll try it on a Ubuntu to check at least via LSUSB if the device exists. I don't think the problem is SD-Card related, because I've also had this strange reset when I tried to change filament a couple of minutes ago...

2) Yes I thought I had a multimeter until today, it seems broken... Tested it a couple of minutes ago, the display does not work... No luck these days... I will get a new one as quick as possible (this evening probably)... And yes, I know how to use it... My studies where electrical engineering (and working now in IT-Business as well as working some Arduino and similar projects my free time), so I'm quite comfortable in doing some measurements...

In the meantime I will have a look at the schematics...

 

[clews 0]

No luck with USB printing... Neither Windows/Linux/MacOS, the printer is recognized (Arduino) by the system but Cura does not allow me to print...

I connected an OctoPi just to see if the printer can be connected, and it worked, at lease for raising the noozle temperature...

Do you have any favourite points for measuring the voltages? Perhaps without unmounting the board?

 

[gr5 2,270]

Do you have any favourite points for measuring the voltages?

 

You should be able to do it all from the back. Look at the schematic that I posted above. I don't know where all the good test points are. 19V obviously at the connector.

 

[clews 0]

Okay... Did some basic measurements, but could not manage to measure while the error occurs, could not reproduce it until about 35 minutes after the start of a print... But I would have to connect a logging device to give me a voltage curve as well as having connectors to do that (or someone has a better idea?)

I managed to measure the voltages on the following points:

19-24Vdc input: +24.3V

TP43 (+24V): +24,3V

TP45 (+5V): +4.9V

TP37 (+3.3V): +3,26V

When I trigger a buildplate-heatup via the advanced menu, I get +24.3V on TP42-TP43. (Bed was still unconnected, as it was on the prints with resets, so I don't care for the buildplate right now).

All tests above gave exactly the same results while heating up the noozle (wanted to see if there was a small voltage drop (at least on 24V) while heating...

Still no news from support...

I still think there is a problem with the electronics (driver?), because of the strange behaviour after this kinds of resets: The X-Motor does very fast forward-backward movements instead of going into the right direction and is of course very noisy at this moment... It behaves more or less like a physically blocked belt, but after the UM has been turned off and on again, all things get normal...

Or (I don't have much experience with stepper-motors) perhaps the motor has a problem and causes sometimes a short that triggers a voltage-drop and therefore a reset of the board? But this won't explain the reset while heating up the noozle while starting a filament change procedure (reset occured about a second after the click).

I don't have enough equipment (and even time) to do some deeper testing, except someone has another idea?

BTW, the title of the thread is not the right one anymore... Should we open a new one?