Beseler Dichro 45s Repair/Service Manual?

[CMoore]

Me too, me too. Outside of voltage reduction, I'd be curious to study why an enlarger light source would need any kind of fancy circuitry in the first place.

I have wondered the same.
I am NOT an electronics expert. I have just a very Basic Knowledge of AC/DC circuits.
The darkroom timer turns the 120V light source, on and off in the Condenser Heads (doesn't it.?)..... why is it so different in the Color Heads.?
I realize they use a different light source (85V .?)
But i still have the same question.

 

[KN4SMF]

I'm not sure what the actual voltage of a bulb used in a dichro head is. I believe it's 45 VAC, off the top of my head. But regardless... If the enlarger's stock power supply unit has gone bad, then what's wrong with just chunking it and using an ordinary Variac, as used in radio repair? We live in a day and time where power company fluctuations are slight and rare.

 

[MattKing]

The 45S uses 82V, 250 W halogen bulbs. The solid state components are part of the voltage stabilization circuitry.
Folks, these are colour heads - voltage stabilization is important to a production oriented colour printing environment, which these heads were designed for. Even in today's electrical supply environment, voltage stabilization would be necessary if one was using these for a production environment.
The circuitry used for voltage stabilization was current and appropriate for their time.

 

[KN4SMF]

Thank you Matt for that answer. Being a radio man, I'd still like to get my hands on some of that paperwork. I've read these powers problem threads before and can't believe I couldn't come up with a fix when factory parts are no longer available.

 

[CMoore]

Thank you Matt for that answer. Being a radio man, I'd still like to get my hands on some of that paperwork. I've read these powers problem threads before and can't believe I couldn't come up with a fix when factory parts are no longer available.

So we could still do it, but we would need 120V for the fan, and a regulated power supply of 82V (probably DC) for the light.

 

[MattKing]

So we could still do it, but we would need 120V for the fan, and a regulated power supply of 82V (probably DC) for the light.

The instruction manual for the 45S states:
F. STABILIZED POWER SUPPLY The voltage for
the colorhead's lamp and electronics are internally
stabilized over an AC line voltage range of ±10%
from the normal.
(emphasis added by me).

 

[CMoore]

Right, but if you do away with the "problematic" circuit of the Beseler, and made one of your own, today....... i was thinking it would be easier to build an external, regulated power supply of 82 VDC to run the lamp.
But like i say, i am definitely NOT an electronics Guru.

However... Mike has mentioned before, that if you send your 45s head to those guys in Canada ... is it KH.? ... once they rebuild the power supply, it no longer has that problem with failure.
They rebuilt one of mine and it works great, They clean it all out and ... as much as it is possible... Calibrate/Adjust the color dials.

If i had the money to do it over again, i would definitely buy Sanders/LPL.
I REALLY dig the way their neg holders slide in, tight, under the enlarger lens.

 

[mshchem]

The last version of the 45S has more modern electronics. I have one as a backup. I currently use the infamous Beseler Universal 45 head. Additive RGB, closed loop. Has controllers for color and VC. Kevin Brown at KHB REALLY doesn't like these, I have a couple of these heads that work great. When they work best head ever made (MHO) I also have two of these heads that don't work, again 20 year old technology that's ancient history.

My recommendation to my younger photo buddies is to pick up a condenser head. As long as Ilford keeps making paper and filters we will be good. (Oh and get some color filters too )

 

[mshchem]

Here's what they look like. These are part of my strategic reserve. US half dollar 30mm 90% silver, current melt value 6 bucks. Colorheads going to hell, money going to hell, what's next

 

[Rostyslav]

Hello,

Excuse for upping the topic. May I have the schematic too, please?

Thanks for advance.

 

[Gino Battiston]

HI. I´m into trouble with my 45s. So sad... Trying to get into the problem. Light flashes BUT, I had a conversation with Kevin Brown from KHB Photografix Canada via email, he looked at the video of the fault and told me: "Looking at the video I am not sure the problem is with the Vactrol units or even the PCB assembly". (I don´t have the video at hand right now)

It started to fail when the lever that pushes the color filters up (white light) was touched. You can hear a mini-switch operating at the end of the lever range, when it´s supposed to activate white light. The movement flashes or interrupts any light, causing some kind of short-circuit that affects the whole system. Very similar to the vactrol issue symptom.

If anyone could guide me the correct disassembly order to reach the lever down there... I´m just taking breath before I start. I gess the problem is the contact in the switch. I do electronics so I can also desolder those vactrols if the time comes.

These are part of my strategic reserve.

Where do I found those vactrols these days?
If some good soul could send me a copy of that holy schematics, that would be beautiful, thanks!
I´m trying to keep my Beseler alive.
THANKS a lot for any info.

 

[mshchem]

First of all. The white light switch has a "paper saver circuit" . If you focus with white light, (filters out of light path), the enlarger lamp will not light until you put the filters back in place. This is to prevent the user from exposing paper without filtration.

The Vactrol opto-isolator problem.
1. With filters in use, white light lever not engaged.
2. When you hit your timer to expose the paper, there will be a delay.
3. At first the delay may be less than a second, as things get worse the delay will get longer.
4. Eventually the delay will become completely random. Total failure will occur at some point where you will get no light.

It sounds like you have a dirty or faulty micro switch on the white light lever. The Vactrol thing is random shouldn't happen by touching the white light lever.

 

[CMoore]

First of all. The white light switch has a "paper saver circuit" . If you focus with white light, (filters out of light path), the enlarger lamp will not light until you put the filters back in place. This is to prevent the user from exposing paper without filtration.
.

Sorry, i am lost...probably because i have never used that lever.
How or when will the lamp activate (via that lever) with no filtration.?
Thank You

 

[mshchem]

Sorry, i am lost...probably because i have never used that lever.
How or when will the lamp activate (via that lever) with no filtration.?
Thank You

OK
Start.
1. Turn on power.
2. Hit the focus button on timer, this turns on the lamp .
3. Throw white light lever to pull filters out of light path, allows you to focus with bright un-filtered light .
4. Hit the focus button on timer to turn off lamp.
5. Forget that you have NOT returned the white light lever back to engage filters. This is what gets people. If after focusing with white light and you forget to return the lever to normal the enlarger lamp will NOT light when you hit expose on your timer.
6. Remember to return the lever to engage the filters, hit the expose button on the timer and the lamp lights instantly for the prescribed time then shuts off.

This is the invaluable Paper Saver Circuit. Imagine you are portrait photographer in 1985. You get ready to print 100 identical 5x7 prints, you know the exact filtration and time. You insert your negative in your negative carrier start to adjust composition and focus. Ah, if I flip the white light lever it will pull the filters out of the way. You adjust the focus and composition, reset the lens f stop to f 8. BUT FORGET TO RETURN THE LEVER TO ADD THE FILTERS BACK. When you hit expose nothing happens, and you realize, before you make 100 bad exposures, that you forgot to put the lever back in place.

This was a great feature, the orange mask and colors of color negative film required bright light for focusing. God forbid you were a humble printer and you screwed up a big batch of prints that took 2 hours to expose and 2 to process only to find out you forgot to "lower the landing gear before touchdown!"

That's it.

 

[CMoore]

OK
Start.
1. Turn on power.
2. Hit the focus button on timer, this turns on the lamp .
3. Throw white light lever to pull filters out of light path, allows you to focus with bright un-filtered light .
4. Hit the focus button on timer to turn off lamp.
5. Forget that you have NOT returned the white light lever back to engage filters. This is what gets people. If after focusing with white light and you forget to return the lever to normal the enlarger lamp will NOT light when you hit expose on your timer.
6. Remember to return the lever to engage the filters, hit the expose button on the timer and the lamp lights instantly for the prescribed time then shuts off.

This is the invaluable Paper Saver Circuit. Imagine you are portrait photographer in 1985. You get ready to print 100 identical 5x7 prints, you know the exact filtration and time. You insert your negative in your negative carrier start to adjust composition and focus. Ah, if I flip the white light lever it will pull the filters out of the way. You adjust the focus and composition, reset the lens f stop to f 8. BUT FORGET TO RETURN THE LEVER TO ADD THE FILTERS BACK. When you hit expose nothing happens, and you realize, before you make 100 bad exposures, that you forgot to put the lever back in place.

This was a great feature, the orange mask and colors of color negative film required bright light for focusing. God forbid you were a humble printer and you screwed up a big batch of prints that took 2 hours to expose and 2 to process only to find out you forgot to "lower the landing gear before touchdown!"

That's it.

.....got it... Thank You

 

[mshchem]

Trust me, if you don't use the colorhead for a couple weeks, or months you will find yourself scratching your head. I wish I had a jillion dollars, I would love to see and try Beseler's new cold LED Dichro L head. Full white LEDs with dichroic filters. Not RGB LED arrays.

 

[CMoore]

Trust me, if you don't use the colorhead for a couple weeks, or months you will find yourself scratching your head. I wish I had a jillion dollars, I would love to see and try Beseler's new cold LED Dichro L head. Full white LEDs with dichroic filters. Not RGB LED arrays.

I did not realize Beseler was still in business.
Are you talking about this head that fits a Beseler 45.?
Looks like it has an external power supply, or is that something else.?

https://www.freestylephoto.biz/8278...o-LED-Color-Head-for-45MXT-or-45VXL-Enlargers

 

[mshchem]

I did not realize Beseler was still in business.
Are you talking about this head that fits a Beseler 45.?
Looks like it has an external power supply, or is that something else.?

https://www.freestylephoto.biz/8278...o-LED-Color-Head-for-45MXT-or-45VXL-Enlargers

Yep, that's it. It's a big box. The price has dropped considerably since it was first announced. I think the prime target customer is education, and we all know what's going on with the chaos of pandemic and remote teaching etc. I would really like to see a review of this, maybe Silvergrain Classics could get a look at one. My concern with something like this is long term support. I've got color heads that work. I'm mostly interested in a variable contrast constant exposure head. I can do this with my colorheads I have now, and an occasional color print for fun.

 

[btaylor]

I have a Beseler Dichro 45 head. When I bought it from one of the members here he packed the circuit boards (left in place) very carefully and advised careful re-installation as poor connection where the three boards plug in to the main board is a common problem. Several times I have had odd behavior with the head- LED value indicators not illuminating or with weird values, or a delay in the lamp coming on, or no illumination at all. I dread the Vactrol failure and finding a replacement. Yet each time removing and cleaning the board connections has corrected the problem. I have been lucky so far and I wanted to pass on some valuable advice. I don’t have the 45s head so I don’t know if it is similar inside.

 

[Kelcey Bauer]

Schematic for the power supply sent via e-mail.

Would it be possible to also get the service manual as well?

thank you
~Kelcey

 

[Rostyslav]

I have an old Dichro head from the USA. So, I had to throw out the fan, electrical plates, and use a halogen lamp for 24V who connected to the power supply 220v -> 24v. There isn't anything that you couldn't repair, except for small color glasses.
P.S. I have no manual

 

[Darkroom David]

Hello. Looking for help with my Dicrho 45s color head. It is blowing bulbs. I cleaned all the contacts and measured the voltage at the bulb connections. Voltage is a steady 94 volts. The unit uses 82V 250 W bulbs. Does anyone know the spec output voltage to the bulb socket? If the voltage is correct then the bulbs were both bad. I would have thought the voltage to the bulb socket would be 82V. but I don't have the single line or the specs for the unit. Thanks. David

 

[Darkroom David]

Would it be possible to also get the service manual as well?

thank you
~Kelcey

Kelcey, did you end up getting the service manual? I am looking for some info on the output voltage at the bulb socket

 

[mshchem]

I have an old Dichro head from the USA. So, I had to throw out the fan, electrical plates, and use a halogen lamp for 24V who connected to the power supply 220v -> 24v. There isn't anything that you couldn't repair, except for small color glasses.
P.S. I have no manual
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Those little springs on the filters are difficult. These old ones are analog, no chips. You choose well to get rid of the circuit boards, very obsolete components.

 

[Amanda B]

Hi David - and everyone,
Did you ever figure out why your enlarger was blowing bulbs? I have two Beseler Dichro 45s heads in our university darkroom that are doing the same thing. Correct bulb, wattage, etc. They just keep literally exploding the bulbs. I am not an enlarger repair woman, but trying to learn enough to get by. I have a color darkroom class this semester, and I'd like to have all our enlargers working instead of being 2 short...