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Thread: Problem with Beseler Universal VC head

  1. #1

    Problem with Beseler Universal VC head

    I recently picked up an excellent-looking Beseler 45 Universal VC head for a decent price. The seller advertised it as working correctly. I don't have a manual (yet--ordered one from KHB), and I've not used one of this exact type before, so I'm not sure exactly what to expect. This is what happens with I turn it on:

    https://www.youtube.com/watch?v=kUWv...ature=youtu.be

    The fans spin, I get some random partial digits on the displays, I get a little blue and a lot of green light (looks like maybe a self test), and there's an extended beep.

    Given the condition, I'd like to keep it if it's economically repairable. I'm reasonably electronics-proficient, but I need some pointers.

    Ideas? Sources of better information?

    Thanks in advance.

  2. #2

    Re: Problem with Beseler Universal VC head

    Follow-up questions:

    - anyone ever identified the source for the connector on the head-to-controller cable? As you can see in the video, it appears to be missing the 'shell', and if I end up keeping it, I'd like to replace that.

    - what parts of this system are common between the VC and color versions? The controller is obviously different--anything else? This head appears to have a clear filter in front of the "red" lamp.

  3. #3

    Join Date
    Dec 2014
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    Iowa City, Iowa
    Posts
    1,083

    Re: Problem with Beseler Universal VC head

    Welcome to Beseler Universal 45 head club. I have 4 heads, 2 work reliably. When these work it's the best head Beseler made. No one wants to work on them.

    One thing that's tricky is the buttons stick. I pulled the controller apart and cleaned and very carefully put a few micrograms of graphite on the plastic buttons.

    Kevin Brown at KHB knows as much as anyone about these and he's very wary of these. The only difference between the VC and color heads is a red dichroic filter. These are RGB closed loop heads. There is a sensor in the head, you can see it if you pull the diffusion chamber out, this controls the intensity of the lamps.

    Could be connections etc. Hard to tell, sometimes it's the head hardware, sometimes the keyboard, sometimes the software, and even the AC supply can make it crazy.

    They are trouble with a capital T, but when they work there's nothing easier.

  4. #4

    Join Date
    Dec 2014
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    Re: Problem with Beseler Universal VC head

    Quote Originally Posted by htroberts View Post
    Follow-up questions:

    - anyone ever identified the source for the connector on the head-to-controller cable? As you can see in the video, it appears to be missing the 'shell', and if I end up keeping it, I'd like to replace that.

    - what parts of this system are common between the VC and color versions? The controller is obviously different--anything else? This head appears to have a clear filter in front of the "red" lamp.
    You are correct, the clear IR cut off filter replaces the red filter that's the only difference.

  5. #5

    Join Date
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    Re: Problem with Beseler Universal VC head

    Quote Originally Posted by htroberts View Post
    I recently picked up an excellent-looking Beseler 45 Universal VC head for a decent price. The seller advertised it as working correctly. I don't have a manual (yet--ordered one from KHB), and I've not used one of this exact type before, so I'm not sure exactly what to expect. This is what happens with I turn it on:

    https://www.youtube.com/watch?v=kUWv...ature=youtu.be

    The fans spin, I get some random partial digits on the displays, I get a little blue and a lot of green light (looks like maybe a self test), and there's an extended beep.

    Given the condition, I'd like to keep it if it's economically repairable. I'm reasonably electronics-proficient, but I need some pointers.

    Ideas? Sources of better information?

    Thanks in advance.
    It's probably not repairable unless you get lucky and find a stuck button. Call Kevin Brown at KHB, he will be your best chance. I would return to seller if possible.

  6. #6

    Join Date
    Jul 2016
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    4,565

    Re: Problem with Beseler Universal VC head

    Let me enumerate some possible issues, from general electronics:

    as it looks that it "reboots"... or it has intermitent power...

    >> One thing I'd check is power suply voltage in the controller board. Check voltage supply in the micro pins, from micro part number you find the datasheet, check voltage in the power pins. It would be good to know what a what the oscilloscope show in the power pins, and in the clock pins.

    > Also when a microproessor is "powered on" the voltage is unstable at the beginning, modern devices detects that "brown current" condition and delays the boot until voltage is stable, old devices use a battery (that also may preserve parameters) to run the microprocessor during a few milliseconds until voltage is stable. If that battery is low then the micro fails to start and the watchdog reboots the micro in cycles: Check if a (usually lithium) battery is there, from part number know the original voltage and measure the actual voltage.

    > If there are parts (chips) in sockets, unplug/plug them, sometimes a bad contact is there. Do that with all connectors inside.

    > Capacitors. In those old boards electrolitic capacitors are a weak link, some start leaking electrolite that would short circuit what in contact. If you see leaks on the board or inflated capacitors this may be repaired by cleaning the board and replacing the capacitor.

    > A too high load. If when booting the micro powers some device/function that is is short circuit this may lower the power supply for the micro making it boot again.

    If you can locate one of those old/good technicians that were repairing old TVs or industrial electroics perhaps there is a chance you can get it fixed.

    In general old digital boards fail from connectivity or from capacitors, the microprocessors are usually fail safe. Other things that may fail are RAM chips and, specially EEPROM chips that store the "program", in that case it would be more difficult to repair, if a EEPROM fails you need an original programmed part.

    ... so I'd check connectivity, battery, power supply and capacitors, other issues may be more difficult to repair.

    I had to try to repair a number of old embedded controllers of similar kind, some were easy to fix, some I wasn't able. Not having the schematics and service manuals is a problem, so you check the easy/common issues that may solve 3/4 of the cases. Old electronics was easier to repair, and thanks to ebay you may even get discontinued parts. Today the higher integration makes it more difficult, you throw away the board or the entire device.

  7. #7

    Join Date
    Dec 2014
    Location
    Iowa City, Iowa
    Posts
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    Re: Problem with Beseler Universal VC head

    One other note. Normal operation, you turn it on the machine is ready to go instantly. It doesn't light up the lamps etc. The most common problem I've had is corroded lamp sockets and pins. Beseler abandoned this product when digital hit, Beseler changed ownership etc. Too bad because these are neat. Next light source I buy will be a Heiland LED setup.

  8. #8

    Re: Problem with Beseler Universal VC head

    Google found me these guys: https://www.controlrepair.com/produc...ntroller/29485

    but am going to call $500 "uneconomical", at least without some significant cost-sharing from the seller (and the listing is for the color controller, not the VC, although I'd bet the electronics are pretty similar).

  9. #9

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    Dec 2014
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    Re: Problem with Beseler Universal VC head

    Quote Originally Posted by Pere Casals View Post
    Let me enumerate some possible issues, from general electronics:

    as it looks that it "reboots"... or it has intermitent power...

    >> One thing I'd check is power suply voltage in the controller board. Check voltage supply in the micro pins, from micro part number you find the datasheet, check voltage in the power pins. It would be good to know what a what the oscilloscope show in the power pins, and in the clock pins.

    > Also when a microproessor is "powered on" the voltage is unstable at the beginning, modern devices detects that "brown current" condition and delays the boot until voltage is stable, old devices use a battery (that also may preserve parameters) to run the microprocessor during a few milliseconds until voltage is stable. If that battery is low then the micro fails to start and the watchdog reboots the micro in cycles: Check if a (usually lithium) battery is there, from part number know the original voltage and measure the actual voltage.

    > If there are parts (chips) in sockets, unplug/plug them, sometimes a bad contact is there. Do that with all connectors inside.

    > Capacitors. In those old boards electrolitic capacitors are a weak link, some start leaking electrolite that would short circuit what in contact. If you see leaks on the board or inflated capacitors this may be repaired by cleaning the board and replacing the capacitor.

    > A too high load. If when booting the micro powers some device/function that is is short circuit this may lower the power supply for the micro making it boot again.

    If you can locate one of those old/good technicians that were repairing old TVs or industrial electroics perhaps there is a chance you can get it fixed.

    In general old digital boards fail from connectivity or from capacitors, the microprocessors are usually fail safe. Other things that may fail are RAM chips and, specially EEPROM chips that store the "program", in that case it would be more difficult to repair, if a EEPROM fails you need an original programmed part.

    ... so I'd check connectivity, battery, power supply and capacitors, other issues may be more difficult to repair.

    I had to try to repair a number of old embedded controllers of similar kind, some were easy to fix, some I wasn't able. Not having the schematics and service manuals is a problem, so you check the easy/common issues that may solve 3/4 of the cases. Old electronics was easier to repair, and thanks to ebay you may even get discontinued parts. Today the higher integration makes it more difficult, you throw away the board or the entire device.
    I'm going to try these suggestions with my faulty heads. I have these for spares. Too bad Beseler's new head isn't something like this.

  10. #10

    Re: Problem with Beseler Universal VC head

    Quote Originally Posted by Duolab123 View Post
    One other note. Normal operation, you turn it on the machine is ready to go instantly. It doesn't light up the lamps etc. The most common problem I've had is corroded lamp sockets and pins. Beseler abandoned this product when digital hit, Beseler changed ownership etc. Too bad because these are neat. Next light source I buy will be a Heiland LED setup.
    I was able to test all three lamps by swapping them into the socket that was coming on the longest, and all three work. They're in good shape with no corrosion.

    I have a Heiland Splitgrade on a V35, but the LED sources are expensive (and have to admit sometimes I like the "old" technology).

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