Unsolvable ER05 + Stuck in Factory Reset Startup

[FancyboyGinswillington 2]

Been looking all over for a solution to the dreaded ER05 for my beloved UM2. It was kind of touch and go for a while, every other print would give me that error (I usually just unplug it for a while and start it up again), but last night it fully decided it wasn't going to print.

 

The switch is definitely working (tested with a Multimeter), motherboard looks fine, tightned any potentially loose connections. Having a hard time figuring out what it could be. I tried a factory reset, and now I'm just stuck in the intro screen because the bed won't go through it's calibration dance.

 

If it's any indicator, I replaced the motherboard with one from ebay a few years back. These past two months I've been printing probably about once a week at a minimum, and am planning on ramping up production pretty significantly (I am a student, and this is currently one my my primary means of producing). 

 

I've got about a month to sort this before my school term starts again. Any ideas?

Edited December 7, 2021 by FancyboyGinswillington

[gr5 2,173]

Did you go to the ultimaker.com/ER05 web page as suggested?  There are some good ideas there.

 

If those don't pan out, maybe remove and re attach the connector to J6?

 

I guess I would use the below schematic and check out TP80.  It should be 5V when the switch isn't triggered and 0V when the bed is down.  If those voltages are correct then it's probably the "arduino" chip.  Meaning you need another PCB.

 

[FancyboyGinswillington 2]

15 minutes ago, gr5 said:

Did you go to the ultimaker.com/ER05 web page as suggested?  There are some good ideas there.

 

If those don't pan out, maybe remove and re attach the connector to J6?

 

I guess I would use the below schematic and check out TP80.  It should be 5V when the switch isn't triggered and 0V when the bed is down.  If those voltages are correct then it's probably the "arduino" chip.  Meaning you need another PCB.

 

The switch is working fine as far as I can tell--tested it with a multimeter, and the screw engages with it just fine.

 

Tested TP80 and I got 4.9V and 0V respectively. Is that close enough, or is the pcb bricked?

[gr5 2,173]

yeah the threshold is probably 2.5V so above 3V for normal and below 1V for closed is definitely close enough.

 

Well you could check the other side of R111 or just remove that cap (C92) in case it shorted out (unlikely) but I think the mega2560 chip is dead.  This is extremely rare.  Bad news.

[gr5 2,173]

Or maybe the firmware is borked and you just need to reload the firmware one more time.

[FancyboyGinswillington 2]

Downloaded the latest version of Cura and updated the firmware, no dice. 

 

Do I just need to check the resistance of R111 or the voltage running across it? The cap looks fine, unless it's an internal short. Might be able to pop it off, have to see if one of the shops at school has a rework station.

 

I happen to have spare MEGA2560 board that I rarely use. Hypothetically, could I pop the chip off that and replace the one on my potentially busted pcb? (I have several years of microelectronics experience, so this isn't particularily challenging).

[Torgeir 242]

Hi @FancyboyGinswillington,

 

Does the Z stepper move at all?

I would do a factory reset first.

Also the stepper driver might be the one failed.

If you have the PCB with "the" original five stepper drivers (the extra extruder E2), it might be possible to redict the Z using this "free" E2 driver.

(There is a complete wiring for this UM2 to be used, -as you're familiar with electronics..)

 

Thanks

Torgeir

 

Edit: If you measure the voltage at the other side of the R111, you will see the switching voltage for PA7. If this voltage is zero all the time due to a short in the cap, then it is easy. ref: @gr5.

So not needed to pull off the Cap.

 

Good luck.

 

 

Edited December 8, 2021 by Torgeir
Added info.

[gr5 2,173]

yes as torgeir says - you should see the exact same voltages on either side of R111.  The cap just filters out noise a little bit.  It's probably not even needed.  But in theory it could short.  In practice - very very unlikely.

 

Torgeir makes a very good point.  Maybe the switch is read fine by the arduino and instead it's the z stepper that isn't moving (usually due to the stepper driver).

 

Do you get to the menu system?  Or does it lock up even before that point now?

 

You should be able to home just the Z axis.  Better firmware would be tinkerGnome's version found here.  It has lots of more options:

https://github.com/TinkerGnome/Ultimaker2Marlin/releases/tag/V19.03.1

 

[FancyboyGinswillington 2]

4 hours ago, Torgeir said:

Does the Z stepper move at all?

Also the stepper driver might be the one failed.

 

If you have the PCB with "the" original five stepper drivers (the extra extruder E2), it might be possible to redict the Z using this "free" E2 driver.

(There is a complete wiring for this UM2 to be used, -as you're familiar with electronics..)

 

Edit: If you measure the voltage at the other side of the R111, you will see the switching voltage for PA7. If this voltage is zero all the time due to a short in the cap, then it is easy. ref: @gr5.

 

Nope. Z doesn't budge. I swapped the Y and Z motors and neither moved. 

 

I'm not sure what rev of the pcb I have, will take a closer look and report back. 

[FancyboyGinswillington 2]

1 hour ago, gr5 said:

Torgeir makes a very good point.  Maybe the switch is read fine by the arduino and instead it's the z stepper that isn't moving (usually due to the stepper driver).

 

Do you get to the menu system?  Or does it lock up even before that point now?

 

You should be able to home just the Z axis.  Better firmware would be tinkerGnome's version found here.  It has lots of more options:

https://github.com/TinkerGnome/Ultimaker2Marlin/releases/tag/V19.03.1

 

 

Stepper driver is on my suspect list.

 

Had a spare stepper so I popped it into the Z-axis port and gave it another go, still nothing.

 

Prior to my factory reset I was able to access the menus just fine, but every time I went to start a print or move the bed it would lock up and spit out ER05. In hindsight I should have at least checked if the heaters were working, that might have given a bit more insight as to the specific problem.

 

I'll give the tinkerGnome firmware a go and report back.

Random question: does the heat from the bed get absorbed into the pcb at all? I realized it being directly under the bed when heating it might cook the parts over time (especially since it begins heating in the lowered position). Overall I'm really not crazy about the pcb access and wiring, it's such a pain to take the damn thing apart, I might just look into making some alternative housing for it.

Edited December 8, 2021 by FancyboyGinswillington

[Torgeir 242]

Hi @FancyboyGinswillington,

 

I've come to think about a failure I got on my UM2E+.

Got the same indication as you had in the beginning.

In order to get the printer working, I had to re switch the power switch sometimes several times to have it working..

One day this was not possible, -just as you describe.

Anyway, after some fault tracing I found that the 24 VDC power relay was not working.

So first thing, check that this relay is delivering power to all stepper drivers and to the heaters.

If this one fails, the failure you have will be the same.

 

I'll think the power supply switching circuits is more or less the same in all PCB versions of UM2 series (except Connect).

 

Maybe this could be your problem.

 

Good luck.

 

Torgeir

 

Edit: Forgot your random question.

I'm never afraid of this as I have installed two fans (2 * 12) VDC in series, which keep the PCB "cold". But you have a good point there .. 🙂

 

 

Edited December 8, 2021 by Torgeir
Additional text.

[gr5 2,173]

Yes!  That's a likely issue!  I though tit was only the Z switch but this could be the 24V supply which powers only the steppers and heaters.  And the side fans.  Nothing else - the display will work fine.

 

Usually it's the relay (K1).  more info here including a video:

 

 

[gr5 2,173]

Oh - and in this other thread I also show how I just bypassed K1.  This jumper is still there on my printer, lol, years later.  I forgot about it:

 

[Torgeir 242]

Oh., man, "Gunnar".

 

I'll think, we've discussed this issue a while back.

We just discussed this and you said there is no need for this relay, -only needed in the "wood" versions (for fire protection)..

 

I'll hope this is the problem, -it will be an easy fix to do. 🙂

 

Thanks

 

Cheers

Torgeir

 

 

[FancyboyGinswillington 2]

On 12/10/2021 at 1:27 AM, gr5 said:

Oh - and in this other thread I also show how I just bypassed K1.  This jumper is still there on my printer, lol, years later.  I forgot about it:

 

 Aye that's the ticket! I had discovered that thread earlier this week and just tested it out, bed moved and everything! 😄

 

Thank you all for your help, I'm *profoundly* happy the fix was so simple.

 

My only followup question: should I bother replacing the relay or will it be fine with the jumper long-term?

 

[gr5 2,173]

I've had the jumper in there for many years and it seems fine.

 

I was chatting with one of the cofounders in New York City at some point years ago, after I had done that jumper.  He stared off into the distance for a bit and said he thought it should be fine.  He said something like "that relay is a safety feature that we never really took advantage of".  It's set up I think so that you can wire something into one of the connectors and tell the printer to cut the 24V but they never added any peripherals or anything to do this.

 

If the printer detects a runaway temperature condition I think it does indeed open up that relay but it also turns everything off anyway so it is a safety feature but I it's only needed if one of the 3 heater mosfets shorts out and won't function properly anymore.