Hi all,
I've acquired an old LS800 (40w) that had a known fault (Laser would not fire at all). I repaired the electrical fault and got the laser working again but it would not run past a certain amount of 'energy'. By that I mean a cut at 50% power and 50% speed would last the same cut length as 25% power and 25% speed before it 'tapered off' in power. The machine only shows just over 1k hours on the laser. According to my research it should be good for 10's of thousands.

I discovered that the first mirror basically had a hole in it so I replaced all mirrors and the focusing lens and performance was a lot better. I could cut for a longer duration but the power still tapers off. I did replace the mirrors with generic gold coated silicon mirrors, which seems to be what the 2 and 3 were made of but mirror 1 was that damaged it was hard to tell if it was different from the rest.

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Further to that, It's not an alignment issue because I can run the same job in the 'bad position' after letting it rest for a few minutes and it cuts fine again. I've also spent several hours getting alignment as close to perfect as I can.

This is my first venture with Co2 Laser and especially RF lasers (I didn't know they even existed until I got this machine)

My Specific question - Is power tapering off during operation an indication that the laser is in need of a recharge? Or, would it be more like the machine loses power over time (more measured in thousands of hours use).

I'm trying to determine the cause of it losing power but an ammeter on the laser power supply indicates its still firing at full power, just not getting the optical power I expect.

OR

Am I just expecting too much of this machine? Ive dabbled with raster engraving at 85% power and it seems ok.

I'm at a loss, I just don't know where to focus my attention in trying to fix this machine - Perhaps the electronic fix was not a complete fix and there is other work needed? Is the laser dying?

Your experience and advice is greatly welcomed.