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Thread: Zone VI Type II 8x10 VC Head Problem

  1. #1

    Zone VI Type II 8x10 VC Head Problem

    Hello,

    I teach analog photography at Keystone College in LaPlume, PA.

    When I started teaching here around 2016, I noticed that there was a Zone VI 8X10 VC enlarger still in the box in our storeroom. This was never set up, or even opened from when it was ordered from Zone VI in January of 2001.

    I decided to set the enlarger up, as I have a 5x7 Type 1 that I use and love it. This one is a Type 2 chassis.

    The setup and everything went fine but when I plug everything in, I am running into issues. When I turn on the power switch on the head, the green lamp is on all the time. If I switch the contrast control box to focus, it goes to white light. Otherwise, it's always on green. Turning the contrast control knobs does not affect the light output at all. Neither does the Brightness dial on the Variable Contrast Control box. This is the case whether or not the switch on the timer is set to focus or not. The head is always on. The directions stated that the head has a safety switch that will cut power after the lamp is on for more than 3 or 5 minutes. I left it on for over 10 to check and the power never went out.

    I verified that the power cord on the head is plugged into my power strip and the other "power" cord is plugged into the timer.

    Based on the invoice that was attached to the boxes, this was purchased in January of 2002 and sat in the boxes for the next 15+ years.

    The timer is the Zone VI Compensating Timer. I am leaving the Print/Focus switch on the timer on Print and I have the light intensity on the timer on Max.

    I did reach out to Richard Ritter and he states:

    "I was not at Zone VI when the Type 2 was designed. It has custom built parts that are not available any more. Most who have this enlarger have taken the guts out of the head and put in LED lights."

    I opened up the head because I figure I can't break it any more than it is and I did not see any damaged parts or wires or anything out of the ordinary on the circuit board.

    Anyone have any ideas? I did take the diffusion plate off to see the actual tubes and when it's set to "Focus" and appears to be all white light, that is the only time both tubes are lit. So I know there is power to the second tube.

    The images show the inside of the head. The black thing on the left seems to control the blue tube while the one on the right controls the green. I know can tell this as the wires coming from the bottom go to the two ends of each tube.

    The one photo shows both tube ends. When its just on power and should not have any light on at all, the green is always on (second photo). When I turn the contrast control box to focus, the blue tube lights up. Both are now on at full power (third photo). The only time that the lights are off is when I shut the power completely off at the head.

    Any ideas on what I can do? I hate to have a giant paperweight.
    Attached Thumbnails Attached Thumbnails processed-9b5cc449-d264-4d4c-8642-cc7c8e904e4d_A2XMYU4b.jpg   processed-4b3988f4-e37c-4cfb-af9c-0522e9ff3c8a_rlCc2vCK.jpg   processed-6b49b298-e8af-4d54-bc8c-b786df1423f6_LwGHOhYX.jpg  

  2. #2
    Eric Woodbury
    Join Date
    Dec 2003
    Posts
    1,637

    Re: Zone VI Type II 8x10 VC Head Problem

    I had the Aristo version for a time. Long ago. It was a simpler design than this, so probably no correlation.

    When you say "white light", I have to assume that is blue + green as there is no white tube in this unit.

    The black things are probably high voltage ballasts to start and drive the tubes. The transformer there makes the power for the circuit board. (If you have a volt meter, check the circuit voltage -- NOT THE BALLAST VOLTAGE -- to be sure that is working. If not, call your engineering department.)

    It is not a paperweight. The tubes light and there is no flicker, so the tubes are fine. The circuit board looks new, too. Not sure what all the circuitry is for. It's a lot of parts for a simple task, but many of Fred's electronics were this way. I'm curious about the red wires that are flying above the circuit board. Maybe they are a fix for an error in the original board or maybe it was designed this way. You can verify this (sometimes) by looking at the solder work where the wires land. Factory wires should have clean solder connections. Also, the silkscreen on the circuit board will indicate a letter/number where the wires land. I forget the letter for wires, but R is for resistors, C for caps, etc.

    It sounds like all these electronics are in the head. Where are the controls? Are they a separate box? Or are they on the front panel of the head similar to the Oriental VC head?

    Does anybody have a schematic of this beast?

    Be sure that all the little connectors are fully engaged. Make sure it is not plugged into the wall when you are inside this thing. The ballasts are several thousand volts at startup. And always 'keep one hand in your pocket' if it is plugged in. This is an old adage to keep from getting shocked.

    Repeat, it is NOT a paperweight. Hang in there. All your problems could be a connection between the board and the controls or a faulty power supply. The fact that everything looks new indicates it is something simple and not a massive blowout. No burn marks is a good thing.

    EjW

  3. #3

    Re: Zone VI Type II 8x10 VC Head Problem

    It is essentially brand new. It was never opened since the school ordered it in 2001 until I unpacked it from the original packaging just before COVID hit.

    The timer works as it should and the contrast control box is a separate box with a Soft, Hard, and Brightness dial. None of the dials do anything at all when adjusting and the only thing that seems to do anything is when I turn the Focus switch on the contrast control box and it turns on the blue tube. This is the only time the blue tube comes on. Either when I turn the focus switch on on the contrast control box or when I turn the focus switch on on the timer itself. Otherwise, the blue light will not come on at all and the green stays on all the time. It will never go off. :-/

  4. #4

    Join Date
    Dec 1999
    Location
    Forest Grove, Ore.
    Posts
    4,674

    Re: Zone VI Type II 8x10 VC Head Problem

    I think that it would have been better not to open up the box until after beginning this thread. Can you put it all back together?

    I have the Type II 8x10 head. If both the green and blue lights are turned on, as one changes the dials, there's not that much perceivable difference in the color of the light. (There is some, though.) It's possible that your head was operating within spec. The Type II works very differently than the Type I. With the Type I, as one changes the knobs, the color of the head changes from deep blue to deep green.

    There are two switches by which to turn on the head's light. One is labeled "Focus" as I recall. The other is a toggle that's pushed down just long enough to begin the timer, and then released. (Or, one can attach and use the foot switch which basically works in the same fashion.) The focus switch results in a bright white illumination for focusing the image.

    I'm pretty sure that I have a manual for the Type II 8x10. (Though, not positive.) If you can message me your address, I will send a copy.

  5. #5

    Re: Zone VI Type II 8x10 VC Head Problem

    Quote Originally Posted by neil poulsen View Post
    I think that it would have been better not to open up the box until after beginning this thread. Can you put it all back together?

    I have the Type II 8x10 head. If both the green and blue lights are turned on, as one changes the dials, there's not that much perceivable difference in the color of the light. (There is some, though.) It's possible that your head was operating within spec. The Type II works very differently than the Type I. With the Type I, as one changes the knobs, the color of the head changes from deep blue to deep green.

    There are two switches by which to turn on the head's light. One is labeled "Focus" as I recall. The other is a toggle that's pushed down just long enough to begin the timer, and then released. (Or, one can attach and use the foot switch which basically works in the same fashion.) The focus switch results in a bright white illumination for focusing the image.

    I'm pretty sure that I have a manual for the Type II 8x10. (Though, not positive.) If you can message me your address, I will send a copy.
    Thanks. I have the manual that came with it. The hard and soft dials do not do anything at all. I also checked by looking directly at the tubes while turning them. The blue tube ony comes on when it's set to focus. Otherwise, it's only the green tube and it won't turn off. Even when not exposing. As long as the power switch is turned on, the green light is on full bast.

  6. #6

    Join Date
    Jun 2014
    Posts
    2,084

    Re: Zone VI Type II 8x10 VC Head Problem

    > I did not see any damaged parts or wires or anything out of the ordinary on the circuit board.
    Doesn't surprise me; there's many failure modes that don't involve any visible signs to the PCB or its parts.

    > I'm curious about the red wires that are flying above the circuit board.
    Looks like the designated connection between the dimming ballasts and the PCB logic. Given the number of leads, I'm guessing these ballasts take a 0-10V analog continuous signal for dimming.
    No, it doesn't look like a PCB error fix at all.

    > Does anybody have a schematic of this beast?
    This is the million dollar question.

    The $100k question is, does someone have the patience to trace out a schematic? It's probably a double-sided PCB and there are only through-hole components. I.e. with some patience and a continuity tester you can trace out the schematic of this thing. It takes a few hours to get it done.

    A schematic is the first requirement to start analyzing what the control logic does and doesn't do. From there, it's a matter of tracking down one or several causes of the problems.

    Keep in mind that the connection between the contrast control box and this lamp driver unit needs to be checked for correct functioning as well. Odds are that the defect is isolated in just one part, and probably the PCB we're shown here, but there's no guarantee. Especially in case of a cascading failure, several components across several boards can be damaged.

    While this may not be a paperweight as it is, it will take hours of careful work to track down the problem. In case one or more logic or ASIC IC's are dead, there may or may not be replacements for them in the marketplace. If not, it means a partial redesign or adaption must be made.

    Depending on the complexity of the problem, it may even be quicker to replace the light source with LEDs. Frankly, I'd seriously consider that route anyway. Invest a lot of time in fixing this beast, only for one of the tubes or ballasts to burn out in a few years and you'll find yourself scavenging the marketplace for NOS items that haven't been manufactured anymore for decades. I know what I'd do. Gut it, sell of the remaining parts to those who are in the position you'd otherwise would be a few years down the road, and revamp the enlarger to a working state with modern control electronics. That is, if you have access to someone who will help you with this. Then again, fixing this thing will require a similar set of competencies...

    Good luck; things like these can be frustrating sometimes. You think you've got something really nice, but what you have in reality may just be a massive liability.

  7. #7

    Join Date
    Mar 2002
    Location
    now in Tucson, AZ
    Posts
    3,613

    Re: Zone VI Type II 8x10 VC Head Problem

    You might contact Richard Ritter, who was a key player at Zone VI. Find him at www.lg4mat.net

  8. #8

    Re: Zone VI Type II 8x10 VC Head Problem

    Already did. His response is in the post. He didn't work at Zone VI at the time the type 2 was created

  9. #9

    Join Date
    Dec 2014
    Location
    Iowa City, Iowa
    Posts
    1,694

    Re: Zone VI Type II 8x10 VC Head Problem

    I have one of these heads, works great. I don't have a clue. I would try to eliminate the timer. This was about the time that the world got serious about eliminating lead (Pb) in electronics.
    I would be very cautious, once something breaks......

  10. #10

    Re: Zone VI Type II 8x10 VC Head Problem

    Quote Originally Posted by Duolab123 View Post
    I have one of these heads, works great. I don't have a clue. I would try to eliminate the timer. This was about the time that the world got serious about eliminating lead (Pb) in electronics.
    I would be very cautious, once something breaks......
    Don't suppose you'd want to get rid of it lol ����

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