Hi, our research group is using an older Olympus FV1000 confocal microscope and an BX-UCB Olympus control box. Today, an error message appeared stating ‘failed in changing light path. please confirm the state of H/W’. The control box is flashing red on the ‘error’ and blinking over the ‘NP’ tab. We haven’t been able to fix this problem - any ideas on what is going wrong here? What does the state of H/W refer to? Thanks for the help 
Oh, that sounds frustrating. I don’t have direct experience with this error, but it sounds like a component involved in switching from eyepieces to confocal imaging is either (a) not moving to the correct place or (b) the sensor that confirms it has moved to the right place has failed. Given the blinking on the control box, my first guess is (a). The microscope configuration (upright or inverted) confocal scanhead mounting location on the microscope will determine what parts need to move.
- On an inverted microscope with a side-mounted scan head, a prism within the microscope body moves to change between the eyepieces and confocal imaging. There is also a position within the fluorescence filter turret that is required to ensure there’s an open hole.
- On an inverted microscope with a back-mounted scanhead, it’s usually a specific position in the fluroescence filter turret with a mirror for the confocal.
- On an upright microscope, there is a specific position in the filterwheel and either a prism or a shutter to prevent laser from getting to the eyepiece.
To troubleshoot this, I would reboot the hardware but leave the software unloaded. Then use the manual controls for the microscope on the body or remote pad to see what causes the control box to blink.
Good luck and keep us posted.