LPL 6700 Dichroic Lightsource - Yellow Filter will not engage

Todd Barlow · Apr 24, 2023

Hi all:
I have searched for a repair manual online but nothing found, lots of owners manual and how to mount the head on the chassis, but no repair manual.

1)Anyone ever taken apart the head to get access to the mechanism that engages the filters?
2)Any guidance on the removal of the filter knobs and white light switch? Do they pull off? (can't see any set screws that mount them to the shaft)

Thanks in advance.

Todd

Kino · Apr 24, 2023

I had the same problem with a LPL 670, (which isn't exactly the same I know) but after removing the covers, mixing chamber, and lens board, I was able to identify the sticky linkages that controlled the dichroic filters.

I cleaned them with long cotton swabs dipped in 91% alcohol until they freed-up and then put a smidge of synthetic grease on their mating surfaces. After working them repeatedly, they functioned smoothly.

I know this isn't what you asked for, but thought it might be of some use if you cannot find a repair manual.

cowanw · Apr 24, 2023

Mine do not engage well only when they are on Max, so I back off a few points. If that helps!

Todd Barlow · Apr 24, 2023

Thanks Kino.
Do you recall how you got the knobs off?

Hi Bill, the red and blue operate smooth thru the range so I think some mechanism is disconnected for the yellow.

Thanks for your help.

Kino · Apr 24, 2023

Todd Barlow said:
Thanks Kino.
Do you recall how you got the knobs off?

Sorry, no. I don't remember having to remove the knobs, but coming in through the top and bottom of the unit.

Todd Barlow · Apr 24, 2023

Ok Thanks Kino.

MattKing · Apr 24, 2023

Have you reached out to Kevin Brown at KHB?

Todd Barlow · Apr 24, 2023

Knobs pull off.
Mechanism to lift and lower the yellow filter was fine, it just needed to be exercised. Added a bit of lubricant and working fine now.

I have photos but even at 300kb each it will not let me load them (2 images)??

MattKing · Apr 24, 2023

Todd Barlow said:
I have photos but even at 300kb each it will not let me load them (2 images)??

Are they in jpeg format and no more than 1000 - 1200 pixels on the long dimension? That usually works for me.

Todd Barlow · Apr 24, 2023

Thanks Matt.

koraks · Apr 25, 2023

There might be a spring that pulls on the filter holder and the cam pulls it into the other direction. So by adjusting the dial, you make the cam pull the filter holder against the tension of the spring, holding it in a specific place. The filter mechanism won't work for instance if the spring has become dislodged. This is the first thing I'd check; so dig a little deeper and verify if there are springs present, and if so, if it's correctly fitted on the yellow filter mechanism.
I recently repaired & cleaned a couple of Leitz dichroic filter mechanisms that work in a conceptually similar way. The design is different of course, but the principle is likely just the same.

Todd Barlow · Apr 25, 2023

Thanks Koraks, I thought there was going to be mechanical issue like you have described, fortunately when I check all springs were present and accounted for and in place. The issue was the yellow filter "lifting arm" seemed to be stuck, but once I gently moved it by hand the dial mechanism was able to take over and it worked just like the magenta and blue filters.

koraks · Apr 25, 2023

Cool! Good to hear you've got it sorted

LPL 6700 Dichroic Lightsource - Yellow Filter will not engage

Todd Barlow

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LPL 6700 Dichroic Lightsource - Yellow Filter will not engage

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