For anyone interested, here’s a video (supplier asked for a video so have been filming every power cycle). excuse the noise of me apparently huffing and puffing like a hippo and my kids playing computer games…
I get the error code after pressing one of the pads. If you don’t press a pad and just power down and back on, you won’t get the message.
Next power cycle it seems ok.
Did you contacted Elektron support ?
Nope. I’m still within my 14 days - so it can go back and the supplier can deal with it.
I will try another one and hope that’s all ok 
What did Elektron respond to all these issues? I just ordered mine from Thoman… 
Hi everyone,
First post here, and with the same issue. I created a ticket for that
I copy/paste the elektron reply
« The message “MISSING CAL: PADS” sometimes showing up is also due to a known bug, that has been fixed for the next OS update. »
I experience also booting issue on my unit
« The Analog Rytm MKII sometimes failing to boot is due to a known firmware bug that unfortunately was introduced with OS 1.60/1.60A. If the unit fails to boot - power off and let it rest for at least twenty seconds before attempting to power on again. There are large capacitors inside the Analog Rytm MKII that need twenty seconds up to a minute to discharge after a crash or rapid restart before the unit can boot again. Rest assured that the issue isn’t with the actual hardware and that our developers are working on a fix with the highest priority »
So everything should be ok with the next update.
Brand new unit black mk2.
I can still make music with it and i love it !
So this new version that seems to be on the new Models - 1.6b, is not supossed yet to solve these 2 apparently different (?) issues, right ?
I’ve now submitted a ticket with Elektron as well. Will update here. If it’s firmware then I won’t bother sending mine back to be honest. Sounds bloody fantastic!
I don’t think 1.60b fixed this issue (mine hasn’t). I’d assume it’s a forthcoming update
That would be great news!
Mine had FW 1.6B and still had the issue btw.
Does make me more excited about getting a new one again.
I LOVE the rytm and was so disappointed by this whole thing.
Thanks for sharing
Still happy I send it back tho
I am sorry where did you get 1.60b?
The last official firmware is 1.60a and it fixed the below issue
The device needed to be switched off for an extended period of time to make it boot properly when switching it on again
Here’s the promised update to this story. almost two months late! Sorry folks.
Elektron replied. They said:
The Analog Rytm MKII sometimes failing to boot is a known firmware bug that unfortunately was introduced with OS 1.60/1.60A. If the unit fails to boot - power off and let it rest for at least twenty seconds before attempting to power on again. There are large capacitors inside the Analog Rytm MKII that need twenty seconds up to a minute to discharge after a crash or rapid restart before the unit can boot again. Rest assured that the issue isn’t with the actual hardware and that our developers are working on a bug fix OS with the highest priority. We are also aware that “forcing” the unit to boot by tapping a pad (which works in some situations when this happens) will result in the MISSING CAL: PADS message showing up. The message is in no way indicative of a missing calibration profile in this case. Press NO to close the popup if it shows up.
[minor edit for brevity]
There’s no reason to worry and that we are working on fixing the issues for the next firmware update. The reason the capacitors are discharging is to provide power for the auto-save that happens in case of a crash or if power is cut. The failed boot triggers this and is the reason why the unit needs to rest for ca twenty seconds before it can boot again. The discharge will start over if you instead try to power on before it has completed.
I also reported another issue which seemed related. I wrote:
I had to power cycle the AR2 three time to get it to boot. The first two times it flashed the lights but the screen didn’t get beyond blackness. I let it pause, fully black, for about 10 seconds, then turned it off and left it for 20-30 seconds. The second boot also failed; the third was successful
And they replied:
Sorry to hear that. It sounds like the previously mentioned bug.
I’ve started to wonder if there’s a minor problem with the power switch. Perhaps it quickly connects and disconnects more than once during the throw from “off” to “on”. If it did this, the capacitor bug would get triggered more often.
I’ve also notice that, but I’m thinking I’m paranoid 
I forgot to copy the second reply from elektron on my ticket (8 march 2021):
…I’m sorry you have had to experience this bug while getting to know it, and I hope we will have a fix ready soon. We have seen a pattern of it happening more frequently when a unit is brand new for some reason - and less frequently after a few days. This is something we’re investigating.
Note that stressing the capacitors shouldn’t do any harm, but it can be good to know that they need to discharge fully before the unit can boot again. 20 seconds is usually enough.
I notice also that since 1 month of using mine everyday several hours, the problem seems to disappear slowly (no booting issue or missing pad for this week, and we are Saturday)
The first week that was at least once everyday.
but even with issue, I felt in love with the Rytm, I love the sound, always missed my SP1200 for that, but not anymore.
And it open my mind on what I can do with my OT, it’s a crazy combo.
there is hope 
1.6b came pre installed on the unit.
1.6a and 1.6b did not fix the problem. I think Elektron are saying it’s created the problem.
The issue seems to happen to mine after it’s been off for a long time
Thanks for the extra info @Octagonist
I’m with you in this, my issue has happened mostly after the units been off for a long while, so assumed it was the switch
Thank you for confirming,
I will try mine today ( Grey MK2 firmware 1.60a) - it has been switched off since October.
Do you have the black one?
Thanks for the Info. So considering it’s a Firmware issue, shouldn’t the behaviour be the same for all the Units ?
Expecting mine next week, from Thomann … hope it does not have these issue(s)…if it has i am wondering still if i should just wait for a new FW or send it back…maybe i will contact support if it shows any issues …
Fair point.
Lets hope its just firmware!
