2/6 Checking Optics - how long should it take

Apologies if this thread has been asked/answered. I did a search and came up empty.
Form 3 (early 2019). It has been running flawless. Very well taken care of, I’m the only user.

Q. How long, on average, should it take for the 2/6 checking optics process take? I’ve loaded a print and it’s now over 20 minutes and still hung on this step.

I have tried:
Re-installing older firmware. No change - back to rc-1.20.9-760
Power down/up
Reboot 3x
Cleaned inspected LPU glass - not perfect, but pretty close

Nothing changes. Now at 25 minutes and still hung.

Thanks in advance

Hi @Carter_West,

Thanks for reaching out about this. This does not sound normal, as the Checking Optics step should take no more than a minute or two in my experience. I would advise getting in touch with our Support Team and sharing your printer’s diagnostic logs with them. They will be able to take a closer look and determine what could be causing this issue.

I have exact same thing. Same Form 3 (early 2019).
It is been about 45 minutes (and still going) on Step 2/6 Checking Optics.
Latest firmware installed rc-1.20.9-760

Thanks Jesse. I’ll contact support

after reverting to firmware 1.14.7 (August 16, 2021) printer is printing fine. Maybe the issue is in the latest firmware.?

Thanks Igor. I’ll give that a try. The timing is right. I have not printed since the machine automatically updated the firmware.

Igor. You are newest best friend! The machine is currently running the print.
Jesse, if you’re online - the problem is that the latest update to firmware is bogus and should not be used for the Form 3 (early 2019) machines. Also, is there some way to turn off auto updates? They are truly annoying. And in my case cost me two lost days of production.

Hi Carter_West,

Thank you for the follow-up - I will pass this along to the team and Jesse. I think a good step to get more eyes on this is to update your logs in the support case you have with our team, as the diagnostic logs could help pinpoint why this is happening.

As for turning off auto-updates, I looked into this and there is no current way to do so besides either disconnecting the printer itself, or blocking updates.formlabs.com on your network. I will go ahead and pass feedback along to see if is something to be looked into for the future - thank you for bringing this to our attention.

I think it is a gui glitch. The printer is already on 3/6, heating.
Press abort and then cancel abort (continue). It will show up 3/6.

Best regards



Interesting. Thanks Sacha

Same to me at Firmware rc-1.20.9-760.
I did what Sascha recommended, I aborted the print and ended the abort, the printer was actually already heating, up, crazy shit… Thanks Sascha, very helpful hint…

Hi all,

Thank you for sharing your experience, it does seem like a GUI glitch. Since this does seem to be cropping up a bit more, we advise creating a support cases to help the team investigate more - having more of these instances visible with the printer type and logs can help provide data that could be helpful to the team to see if they are able to pinpoint why this is happening.

Hello, I have already opened sooo many cases with support because the machine was not working properly. I definitely had 3 or 4 replacement printers! Now I have one that works quite well, it squeaks and pops and makes nasty noises but prints ok! I have quite a lot of bumps and dents in the surfaces for example printing technical resin as Tough 2000. With standard resin it creates good surfaces! most of the time they want to tell you that something is wrong with the print object, but i’m sure that’s not the reason!
The one with the GUI glitch is now the newest. If i open a case, should i refer to the posts on the forum here?

Hi @charger_01,

I’m sorry to hear about the rough experience you’ve had in terms of printer replacements. The issues you’re encountering now are something our Support team could help narrow down. If you do make a case, feel free to share a link to this forum thread. With that said, Support may request other information such as videos, print files, or diagnostic logs to better understand the issues.

I have hit this issue twice in the last couple of days. There is a simple workaround. Hit “ABORT” when the printer is stuck at 2/6, and then when the “are you sure” dialog comes up, hit “CANCEL” and the printer will exit the checking optics state and move to pre-heat like it’s supposed to.

Another way around is to prime your printer first. Optical checks are then done already.

Hi all,

Thank you for sharing your experience.

5-10 minutes on this step is expected as the printer is still going through the process - I did pass along this feedback to the team as this does seem a bit less intuitive in terms of user experience.

If you are experiencing a longer time than 10 minutes, it’s best to get that looked in a support case as this could indicate other underlying issues.

The feedback through support cases will also get help get more eyes on this.

Are you sure? I think the first time I saw this issue, it was with a printer that was primed. I started the job and after an hour realized it hadn’t started. Went down to the workshop expecting to see it was either still filling (resin tank didn’t have a lot left) or heating (if I don’t turn on the heat in my workshop, it gets down to the mid-low 60s and the printer’s heater can’t overcome that to reach printing temp). Instead it was at Checking Optics (2/6). I hit ABORT as that was my only option, but for some reason decided to cancel the abort attempt to give the optics check a little more time. But as soon as I hit CANCEL it went to pre-heat and the print started.

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Thank you to @Randy_Cohen!

Your workaround (ABORT and CANCEL) works for me too.
Hopefully support can fix that problem…


I can confirm that I have had the issue since the firmware update and the Abort/Cancel will move to the next screen.

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