Leitz power unit/bulb troubleshoot

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houstontx
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Leitz power unit/bulb troubleshoot

#1 Post by houstontx » Wed Aug 26, 2015 1:59 am

Hi all,

I have a leitz dialux 20 that has a power control unit which turns on and shows voltage change, but no light from the bulb. Can anyone confirm if I am missing cords from the power unit? Is there any visual indicators that the bulb may be burned out? It looks to be in pretty good condition, not blackened and filament is intact. Just trying to do some due diligence before buying a new bulb.

Thanks,
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gekko
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Re: Leitz power unit/bulb troubleshoot

#2 Post by gekko » Wed Aug 26, 2015 2:09 am

The best way to check the bulb is by using an ohm meter or a conituity checker. If you are checking the filament visually, you should use a stereo microscope or a magnifier and look very carefully as a break in a filament can often be hard to see by the naked eye.
It does look to me from your pictures that the cables/connections are correct.

billbillt
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Re: Leitz power unit/bulb troubleshoot

#3 Post by billbillt » Wed Aug 26, 2015 5:58 am

Gekko is correct... You need to check the continuity with an ohmmeter... Even a cheap one from Harbor freight will do... I have had bulbs go bad and look fine.... At least this would eliminate the bulb as the problem...

BillT

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Oliver
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Re: Leitz power unit/bulb troubleshoot

#4 Post by Oliver » Wed Aug 26, 2015 6:22 am

Hello,
Check the voltage directly at the two "feet" (wires) of the bulb, with the bulb still connected. Maybe there is a problem with the socket to bulb connection due to corrosion. The picture shows that the bulb wires seem to be discolored at the bottom, which could indicate corrosion.

Oliver.
Image Oliver Kim - http://www.microbehunter.com - Microscopes: Olympus CH40 - Olympus CH-A - Breukhoven BMS student microscope - Euromex stereo - uSCOPE MXII

houstontx
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Re: Leitz power unit/bulb troubleshoot

#5 Post by houstontx » Wed Aug 26, 2015 5:25 pm

Oliver,

You were right it was the corrosion at the "feet" they were very dark black and purple. shined them up a bit with steel wool. Works great now!

Thanks!

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KurtM
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Re: Leitz power unit/bulb troubleshoot

#6 Post by KurtM » Wed Aug 26, 2015 11:56 pm

Dang Oliver - good eye! 8-)

Chris - how about pictures of this scope? Show and tell time! :geek:
Cheers,
Kurt Maurer
League City, Texas
email: ngc704(at)gmail(dot)com
https://www.flickr.com/photos/67904872@ ... 912223623/

einman
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Re: Leitz power unit/bulb troubleshoot

#7 Post by einman » Thu Aug 27, 2015 2:28 am

It is a great scope. I have the Dialux 20EB which has the internal illumination instead of the external.

Image
Image


The nose pieces are exchangeable so you can have one mounted with dry objectives and another with oil or phase or darkfield etc. Changing them takes about 5 seconds...

I have wondered how much additional illumination the Dialux 20 has...

houstontx
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Re: Leitz power unit/bulb troubleshoot

#8 Post by houstontx » Thu Aug 27, 2015 2:47 pm

Einman,

It has a 100w max and 100w bulb installed.

Unfortunately my unit looks like it was dropped in transit and the coarse adjustment/stage is stuck just below the focus of the objectives. I read another post about someone with the same problem. Doesn't look fun to fix... This unit is great though, really want to get it working but it has been a pain so far!

einman
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Re: Leitz power unit/bulb troubleshoot

#9 Post by einman » Thu Aug 27, 2015 6:23 pm

Here is a Leitz Dialux EB stand minus condenser starting at $75.00

Ebay....301720454508

I have nothing to do with it other than I am one of the watchers.

You might be able to get it cheaper than fixing the one your have..just a thought.Of course you could end up with another fixer upper..the fun of buying on E-bay.

houstontx
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Re: Leitz power unit/bulb troubleshoot

#10 Post by houstontx » Thu Aug 27, 2015 7:08 pm

Thanks for this, I have thought about getting a new body anyway because the little spring out plastic binocular head holders don't work so well.

I will put up pics of the unit later today.

Thanks,

houstontx
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Re: Leitz power unit/bulb troubleshoot

#11 Post by houstontx » Thu Aug 27, 2015 11:57 pm

well heres how shes looking right now. Just took the back plate off to see if I could access the adjustment gears. Of course not, too easy. Completely encased from the back by what can only be described as salvaged panzer tank armor.

Top two pics show the front plate and black block (with two hex screws) that I am trying to remove to get to the gears.

Bonus was the big bastard objective (63x w/correction) that came with it.

Unfortunately you'll have to TWIST YOUR HEAD OFF to see my pics again, i really dont understand why only my pictures seem to turn sideways, despite showing up correctly on my computer.
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einman
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Re: Leitz power unit/bulb troubleshoot

#12 Post by einman » Fri Aug 28, 2015 1:37 am

That 63X is an apo correct? I have an older version I believe. Or it could just be the angle of the photo. Crap my head just fell off!!! LOL

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zzffnn
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Re: Leitz power unit/bulb troubleshoot

#13 Post by zzffnn » Fri Aug 28, 2015 12:15 pm

houstontx,

You may be able to access/repair the coarse/fine focus mechanism by removing condenser gears and base. It may take you half a day or so. Do take photos for your own record as to how things join each other in which sequence. If you can purchase a replacement stand easily, you may have nothing to lose.

The spring out head holder may be DIY repaired as well - it could be just a rusty spring that needs cleaning and lubrication. WD 40 or white petroleum jelly should help. Do protect glass/lens first and avoid using too much.

houstontx
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Re: Leitz power unit/bulb troubleshoot

#14 Post by houstontx » Sun Aug 30, 2015 2:09 am

Pics from the breakdown. Took the condenser holder and stage off. Each hex bolt took the same exact amount of torque to remove. Very tight, very good quality control. I loosened the hex bolts slightly on the side rails that held the stage block, and that seemed to allow it to move up to the correct height. Great! I thought, I had it fixed. Unfortunately when i buttoned it back up and stood it upright i lowered it down to find the lowest height it could go and it dropped straight to the bottom of the base. Bad news. Had to open it up again, unbolted the rails, and thats when the whole assembly exploded into rails and bearings and hex bolts. Ball bearing hell I'd call it.

Long story short, after hunting for ball bearings for 20 minutes I put the rails back together and turned the coarse adjustment up as far as it would go (a gear mechanism stops the knobs from turning past the point the block will hit the top). Then installed the block and rails assembly by using duct tape to hold the three pieces and ball bearings together. And finally, I have a fully functioning leitz dialux 20.
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zzffnn
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Re: Leitz power unit/bulb troubleshoot

#15 Post by zzffnn » Sun Aug 30, 2015 3:10 am

Houstontx,

All the suddent I member this:
I had similar experience with my AO Series 4, except that mine did not explode and sinking/backlash was mild. I had no experience with Leitz though.

My AO4 came with a very tight coarse focus (its fne focus is a separated mechanism and works perfectly). I loosened the 2 screws holding the corase focus mechanism and the stage began to have backlash/sinking. There was an elusive balance between being too tight and backlash/sinking - I never got it perfect and ended up erring on being slightly too tight. An impact to the scope can also knock my coarse focus into sinking.

I suspect I need some heavy damping grease to find that perfect balance between smoothness and brightness ( heavy grease is needed between tight mechanisms - I used white petroleum jelly, which is probably too light and not the right lubricant).

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gekko
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Re: Leitz power unit/bulb troubleshoot

#16 Post by gekko » Sun Aug 30, 2015 8:33 am

and thats when the whole assembly exploded into rails and bearings and hex bolts. Ball bearing hell I'd call it.....And finally, I have a fully functioning leitz dialux 20.
Congratulations! Wonderful!

billbillt
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Re: Leitz power unit/bulb troubleshoot

#17 Post by billbillt » Sun Aug 30, 2015 9:51 pm

I have used "Vaselene" to good effect... I have had no trouble with it...

BillT

houstontx
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Re: Leitz power unit/bulb troubleshoot

#18 Post by houstontx » Sun Aug 30, 2015 10:26 pm

Vaseline! I kept thinking i needed some heavy grease to keep the bearings in place, i didn't even think about it. Well here is the finished product.
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henryr
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Re: Leitz power unit/bulb troubleshoot

#19 Post by henryr » Thu Sep 24, 2015 2:42 pm

I just bought a dialux minus head, objectives, and light source. Regarding a light source, I'm thinking of making a sleeve with a hole in the center. It would be a slip fit into the bayonet hole, and it's center hole would accept my fiber optic cable light end. I would appreciate any thoughts on this.

Thanks,
henryr

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