I see this too. It’s just a UI bug. The machine is actually preheating but it stays on the checking optics page. If you just wait the print will start normally just as it would if you do the abort/cancel workaround.
1 Like
I’ve noticed this a few times too lately. When the printer gets stuck on checking optics I just abort and restart, then it works fine. This morning it was checking optics for maybe 5min, not sure but then moved on… the print failed though but that’s another matter.
2 Likes
Came here to complain about this delay!
It’s still happening on the very latest Preform+Form3 firmware updates even when primed! 
And yeah, FWIW the ABORT+CANCEL thing “solves” the issue…
Hi @bolsoncerrado,
Thank you for reaching out - I’m sorry to hear that you ran into this issue. As others mentioned above, this seems to be a UI issue where the printer has actually moved on to heating despite the display remaining on the “Checking Optics” step. Our team is aware of this issue and looking into it, and we appreciate your patience in the meantime.
1 Like
Hi Jesse.
I’d like to add a quick tip. During these cold winter days, I found that if I place a small office space heater near the printer and allow it to warm up the area around the machine for about 10 minutes the printer goes from optics to phase 3 just after the bed re-levels (about 2 minutes after start of optics). If I don’t use the small space heater, it can take up to 15~20 minutes to get past the optics - warming phase. Using abort/cancel will change the UI to indicate heater, but never the less, it’s still going to need to come up to temp before moving to the next phase. I then turn the heater off once the printer has begun.
HYN all.
3 Likes
Thank you all for posting this information, the bug hit me today and this work around kept me printing!
1 Like