End of laser tube: not pristine, but cleaning it is a last resort
Starting to suspect the tube
Current is 23-24mA, OK (Max is 26mA)
should be good for 10000 hours
it has had more like 950 power-on hours, over the past two years (installed 2018-12-22)
Try an output power test and see if it's close to its factory-measured 100W; or closer to 50W actual
Ben: Diagnosed loss of bed level: there is vertical movement in the threaded rods under the bed
the rods are not attached to the bearings and can move vertically if there is sufficient room - the floor or the sheet metal of the LC1290 may not be fixed
the movement is limited, not an unlimited slipping of steps or teeth
the rods can be sitting flush down on the bearing, or may be raised up
Extra/thicker shims at the top could remove the slack space
Empty compressor tanks, water trap
TODO: KamilS has solenoid for auto-purge of main tank
stored in LC1290 control cavity
secondary tank and line trap will need occasional purge
Hour meter
The hour meter started from 1.6 hours, at 20171210 , 400-512 beam-active cutting hours per annum