MK2 Laser appears to have melted G2 lens

Hello and just tried my laser for the first time. Followed all of the online instructions and watched the Sienci video several times to make sure I did it right. After one successful 3x5 inch burn, which was a small line picture at 80% dip switch using Lightburn then gSender that took 5 minutes, I found what appears to be a melted spot on the center of the lens. What did I do wrong? I was at the correct Z height and the lens was inserted correctly so any ideas? I also have a 3E lens but found the online documentation different than the video regarding which end goes into the ring - they are opposite but have not tried to see which is which. thanks

@CMonastra What material did you burn the picture on? Could what you are seeing on the lens be some of that material?

Cherry and only used 1 pass and had the 255 setting as recommend. Speed was 24.5 based on the video. I will check if something on lens but never took it out between the first ‘good’ burn and the second where I couldn’t focus. Here is picture of lens sitting on light colored pine showing the spot. Very odd and burning right now with 3E and no issues so far. thanks

@CMonastra I would take a swab with some alcohol to see if you can get that off. I am interested in how you make out as I will be amazed if a diode laser can melt glass. It cannot etch glass unless you paint the glass since the laser simply passes through the glass. I can’t see that being any different with a lens. That said, I have no expertise in that area at all.

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Tried alcohol on a Qtip on both sides but still have the dot. I opened a support ticket with Sienci and will post what they come back with. Could be an imperfection or maybe a scratch on the lens but not sure how that would have occurred. I did have the lens screwed in all the way to the laser but not tight. We will see and did order a replacement plus the 4 lens set to boot. thanks

Replied to your support ticket, we’ll chat soon and fix this.

Hello and Sienci said to clean our lens before use which does make sense. They were very helpful with this matter. Said this is a rare occurrence but “cleaning the lens with isopropyl alcohol before use is always good maintenance”. Thanks and just sharing. Nice work and quick response Sienci Support!