• Re: VCR plays color tapes in B&W only?

    From Charles Lucas@21:1/5 to wire on Sun Jul 10 13:35:55 2022
    On Saturday, April 15, 2000 at 2:00:00 AM UTC-5, wire wrote:
    I am working on my aunts vcr and it just started to play color
    tapes in black and white. I assumed it was just dirty and needed
    cleaning. Took it apart and for the most part it is very clean.
    cleaned up what little dirt there was and reassembled it. Still
    plays tapes in black and white. What are some common things
    that would cause this?
    Thanks
    Peter
    --
    !!!!!!!!!!!Go Build a Robot!!!!!!!!!!!
    ! http://members.home.net/wireb/ !
    !!!!!!!!!!!Go Build a Robot!!!!!!!!!!!
    Peter Shabino Graduated Electrical Engineering
    wi...@home.com Michigan Technological University
    2015 41st ST. NW apt. F13 Now at
    Rochester, MN 55901 IBM card test division
    Check the luminance/chrominance [luma/chroma] circuitry that controls the picture output
    in black and white and color. I would check the 3.58 MHz crystal oscillator also on the video
    output as well. This things help with the color processing. Usually, it is an IC or integrated
    circuit (could even be a flatpack) that controls this or some discreet component like a transistor,
    resistor, or cap. that activates the IC).

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  • From Another idiot on google groups@21:1/5 to Charles Lucas on Mon Jul 11 01:30:26 2022
    Charles Lucas <charlesandmilly@gmail.com> wrote:
    On Saturday, April 15, 2000 at 2:00:00 AM UTC-5, wire wrote:
    I am working on my aunts vcr and it just started to play color tapes
    in black and white. I assumed it was just dirty and needed
    cleaning. Took it apart and for the most part it is very clean.
    cleaned up what little dirt there was and reassembled it. Still
    plays tapes in black and white. What are some common things that
    would cause this?
    Thanks
    Peter

    Check the luminance/chrominance [luma/chroma] circuitry that controls
    the picture output in black and white and color. I would check the
    3.58 MHz crystal oscillator also on the video output as well. This
    things help with the color processing. Usually, it is an IC or
    integrated circuit (could even be a flatpack) that controls this or
    some discreet component like a transistor, resistor, or cap. that
    activates the IC).

    Do you really think that after over 22 years, the poster of the article
    to which you just replied is still waiting around for your answer?

    The article to which you repled was posted April 15, 2000.

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  • From Charles Lucas@21:1/5 to Another idiot on google groups on Mon Jul 11 17:07:59 2022
    On Sunday, July 10, 2022 at 8:30:31 PM UTC-5, Another idiot on google groups wrote:
    Charles Lucas <charles...@gmail.com> wrote:
    On Saturday, April 15, 2000 at 2:00:00 AM UTC-5, wire wrote:
    I am working on my aunts vcr and it just started to play color tapes
    in black and white. I assumed it was just dirty and needed
    cleaning. Took it apart and for the most part it is very clean.
    cleaned up what little dirt there was and reassembled it. Still
    plays tapes in black and white. What are some common things that
    would cause this?
    Thanks
    Peter
    Check the luminance/chrominance [luma/chroma] circuitry that controls
    the picture output in black and white and color. I would check the
    3.58 MHz crystal oscillator also on the video output as well. This
    things help with the color processing. Usually, it is an IC or
    integrated circuit (could even be a flatpack) that controls this or
    some discreet component like a transistor, resistor, or cap. that activates the IC).
    Do you really think that after over 22 years, the poster of the article
    to which you just replied is still waiting around for your answer?

    The article to which you repled was posted April 15, 2000.

    I saw the date (I can read) and I am truly sorry if my outrageously late reply deeply offends you somehow. I never expected either of us to wait and I am sure the original poster never expect me nor my specific answer to be available at any time. I
    posted a reply this late for archival purposes, as VCR's are outmoded now, for the most part. Besides, everyone else has had 22 years to provide some sort of answer (however simple or complex to solve the problem). Some of us when we service peoples'
    tech. needs are extremely busy and do not get around to writing on a forum like this. At any rate, archiving the answer is good for posterity, should anyone at any future time utilize the technology or the information and find it useful. You can perceive
    me as an "idiot" for the outdated response. The fact is I wanted to respond to this and thought I would offer my two cents worth (whether you value the actual input or not). The point is even though the original poster didn't wait for me or answer,
    somehow you did respond with a reply.

    Have a great day. God Bless.

    Charles Lucas

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  • From ohger1s@gmail.com@21:1/5 to charles...@gmail.com on Sat Jul 16 09:49:14 2022
    On Monday, July 11, 2022 at 8:08:02 PM UTC-4, charles...@gmail.com wrote:
    On Sunday, July 10, 2022 at 8:30:31 PM UTC-5, Another idiot on google groups wrote:
    Charles Lucas <charles...@gmail.com> wrote:
    On Saturday, April 15, 2000 at 2:00:00 AM UTC-5, wire wrote:
    I am working on my aunts vcr and it just started to play color tapes
    in black and white. I assumed it was just dirty and needed
    cleaning. Took it apart and for the most part it is very clean.
    cleaned up what little dirt there was and reassembled it. Still
    plays tapes in black and white. What are some common things that
    would cause this?
    Thanks
    Peter
    Check the luminance/chrominance [luma/chroma] circuitry that controls the picture output in black and white and color. I would check the
    3.58 MHz crystal oscillator also on the video output as well. This things help with the color processing. Usually, it is an IC or integrated circuit (could even be a flatpack) that controls this or
    some discreet component like a transistor, resistor, or cap. that activates the IC).
    Do you really think that after over 22 years, the poster of the article
    to which you just replied is still waiting around for your answer?

    The article to which you repled was posted April 15, 2000.
    I saw the date (I can read) and I am truly sorry if my outrageously late reply deeply offends you somehow. I never expected either of us to wait and I am sure the original poster never expect me nor my specific answer to be available at any time. I
    posted a reply this late for archival purposes, as VCR's are outmoded now, for the most part. Besides, everyone else has had 22 years to provide some sort of answer (however simple or complex to solve the problem). Some of us when we service peoples'
    tech. needs are extremely busy and do not get around to writing on a forum like this. At any rate, archiving the answer is good for posterity, should anyone at any future time utilize the technology or the information and find it useful. You can perceive
    me as an "idiot" for the outdated response. The fact is I wanted to respond to this and thought I would offer my two cents worth (whether you value the actual input or not). The point is even though the original poster didn't wait for me or answer,
    somehow you did respond with a reply.

    Have a great day. God Bless.

    Charles Lucas

    You didn't provide any specific help at all, unless you want to consider 'check the color circuitry' and 'it could be an IC, transistor, crystal, resistor, or capacitor' as helpful.

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  • From Charles Lucas@21:1/5 to ohg...@gmail.com on Sat Jul 16 16:15:19 2022
    On Saturday, July 16, 2022 at 11:49:16 AM UTC-5, ohg...@gmail.com wrote:
    On Monday, July 11, 2022 at 8:08:02 PM UTC-4, charles...@gmail.com wrote:
    On Sunday, July 10, 2022 at 8:30:31 PM UTC-5, Another idiot on google groups wrote:
    Charles Lucas <charles...@gmail.com> wrote:
    On Saturday, April 15, 2000 at 2:00:00 AM UTC-5, wire wrote:
    I am working on my aunts vcr and it just started to play color tapes >> in black and white. I assumed it was just dirty and needed
    cleaning. Took it apart and for the most part it is very clean.
    cleaned up what little dirt there was and reassembled it. Still
    plays tapes in black and white. What are some common things that
    would cause this?
    Thanks
    Peter
    Check the luminance/chrominance [luma/chroma] circuitry that controls the picture output in black and white and color. I would check the 3.58 MHz crystal oscillator also on the video output as well. This things help with the color processing. Usually, it is an IC or integrated circuit (could even be a flatpack) that controls this or some discreet component like a transistor, resistor, or cap. that activates the IC).
    Do you really think that after over 22 years, the poster of the article to which you just replied is still waiting around for your answer?

    The article to which you repled was posted April 15, 2000.
    I saw the date (I can read) and I am truly sorry if my outrageously late reply deeply offends you somehow. I never expected either of us to wait and I am sure the original poster never expect me nor my specific answer to be available at any time. I
    posted a reply this late for archival purposes, as VCR's are outmoded now, for the most part. Besides, everyone else has had 22 years to provide some sort of answer (however simple or complex to solve the problem). Some of us when we service peoples'
    tech. needs are extremely busy and do not get around to writing on a forum like this. At any rate, archiving the answer is good for posterity, should anyone at any future time utilize the technology or the information and find it useful. You can perceive
    me as an "idiot" for the outdated response. The fact is I wanted to respond to this and thought I would offer my two cents worth (whether you value the actual input or not). The point is even though the original poster didn't wait for me or answer,
    somehow you did respond with a reply.

    Have a great day. God Bless.

    Charles Lucas
    You didn't provide any specific help at all, unless you want to consider 'check the color circuitry' and 'it could be an IC, transistor, crystal, resistor, or capacitor' as helpful.
    Need a model number to do that. everything is specific to the model. Also,check any and all of those things- if not sure. A good
    service manual for the model would help to track down the critical components that activate the circuit. There are also many different
    integrated circuits and circuits out there and different ways to actuate them (a resistor,a diode, a transistor, or cap, etc...), so it depends on
    the design of the circuit. If I have a model number, I can tell you what pins to check to verify correct operation. I have been a tech. for 32
    years and not all circuits are designed the same. The initial information is generalized as a guide. If you want something more specific, please provide a model number or an FCC ID number. God Bless you.

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  • From amdx@21:1/5 to Another idiot on google groups on Fri Aug 5 14:59:43 2022
    On 7/10/2022 8:30 PM, Another idiot on google groups wrote:
    Charles Lucas <charlesandmilly@gmail.com> wrote:
    On Saturday, April 15, 2000 at 2:00:00 AM UTC-5, wire wrote:
    I am working on my aunts vcr and it just started to play color tapes
    in black and white. I assumed it was just dirty and needed
    cleaning. Took it apart and for the most part it is very clean.
    cleaned up what little dirt there was and reassembled it. Still
    plays tapes in black and white. What are some common things that
    would cause this?
    Thanks
    Peter
    Check the luminance/chrominance [luma/chroma] circuitry that controls
    the picture output in black and white and color. I would check the
    3.58 MHz crystal oscillator also on the video output as well. This
    things help with the color processing. Usually, it is an IC or
    integrated circuit (could even be a flatpack) that controls this or
    some discreet component like a transistor, resistor, or cap. that
    activates the IC).
    Do you really think that after over 22 years, the poster of the article
    to which you just replied is still waiting around for your answer?

    The article to which you repled was posted April 15, 2000.

    With a problem like that, my first shot would be to sparingly,
    start hitting single parts in that area with cold spray, and see if the
    color came back.
    If not, then start troubleshooting. That even had success during the 1980s!

    --
    This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

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  • From Charles Lucas@21:1/5 to All on Sat Aug 6 11:46:32 2022
    The article to which you repled was posted April 15, 2000.

    With a problem like that, my first shot would be to sparingly,
    start hitting single parts in that area with cold spray, and see if the
    color came back.
    If not, then start troubleshooting. That even had success during the 1980s!


    Another technique is to heat the IC up with a hot hair dryer to see if you can get
    it to act up that way. This worked during the 1980's also. Overheating microprocessors
    beyond their temperature coefficients can be dodgy... They can be tricky.

    --
    This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

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  • From Stephen Wolstenholme@21:1/5 to charlesandmilly@gmail.com on Sun Aug 7 13:17:02 2022
    On Sat, 6 Aug 2022 11:46:32 -0700 (PDT), Charles Lucas <charlesandmilly@gmail.com> wrote:


    The article to which you repled was posted April 15, 2000.

    With a problem like that, my first shot would be to sparingly,
    start hitting single parts in that area with cold spray, and see if the
    color came back.
    If not, then start troubleshooting. That even had success during the 1980s! >>

    Another technique is to heat the IC up with a hot hair dryer to see if you can get
    it to act up that way. This worked during the 1980's also. Overheating microprocessors
    beyond their temperature coefficients can be dodgy... They can be tricky.


    I used a soldering iron without any solder to heat individual
    components, hair dryers tended to heat everything up at once. That was
    a long time before the 1980's

    Steve
    --
    Neural Network Software for Windows http://www.npsnn.com

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  • From Jeff Liebermann@21:1/5 to steve@easynn.com on Sun Aug 7 08:28:15 2022
    On Sun, 07 Aug 2022 13:17:02 +0100, Stephen Wolstenholme
    <steve@easynn.com> wrote:

    On Sat, 6 Aug 2022 11:46:32 -0700 (PDT), Charles Lucas ><charlesandmilly@gmail.com> wrote:


    The article to which you repled was posted April 15, 2000.

    With a problem like that, my first shot would be to sparingly,
    start hitting single parts in that area with cold spray, and see if the
    color came back.
    If not, then start troubleshooting. That even had success during the 1980s! >>>

    Another technique is to heat the IC up with a hot hair dryer to see if you can get
    it to act up that way. This worked during the 1980's also. Overheating microprocessors
    beyond their temperature coefficients can be dodgy... They can be tricky.


    I used a soldering iron without any solder to heat individual
    components, hair dryers tended to heat everything up at once. That was
    a long time before the 1980's

    Steve

    Hair dryers, large heat guns, paint strippers, butane torches, and
    flame throwers are too large for heating individual components.
    Smaller is better (mini or micro heat gun): <https://www.aliexpress.com/item/3256802432742384.html> <https://www.google.com/search?q=mini+heat+gun&tbm=isch>
    Personally, I have several temperature controlled SMD desoldering
    stations and adapters with very small diameter stainless tips. It
    took a while to optimize the air flow and temperature settings, but
    works well enough for localized heating.

    I've also thought about building a small IR heater consisting of a hot
    nichrome wire and a polished aluminum reflector to concentrate the
    heat. Because there's no flame or blowing air, it should be able to
    heat individual components without also heating up everything in the
    vicinity. Yet another project.


    --
    Jeff Liebermann jeffl@cruzio.com
    PO Box 272 http://www.LearnByDestroying.com
    Ben Lomond CA 95005-0272
    Skype: JeffLiebermann AE6KS 831-336-2558

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  • From Chuck@21:1/5 to charlesandmilly@gmail.com on Sun Aug 7 10:44:33 2022
    On Sun, 10 Jul 2022 13:35:55 -0700 (PDT), Charles Lucas <charlesandmilly@gmail.com> wrote:

    On Saturday, April 15, 2000 at 2:00:00 AM UTC-5, wire wrote:
    I am working on my aunts vcr and it just started to play color
    tapes in black and white. I assumed it was just dirty and needed
    cleaning. Took it apart and for the most part it is very clean.
    cleaned up what little dirt there was and reassembled it. Still
    plays tapes in black and white. What are some common things
    that would cause this?
    Thanks
    Peter
    --
    !!!!!!!!!!!Go Build a Robot!!!!!!!!!!!
    ! http://members.home.net/wireb/ !
    !!!!!!!!!!!Go Build a Robot!!!!!!!!!!!
    Peter Shabino Graduated Electrical Engineering
    wi...@home.com Michigan Technological University
    2015 41st ST. NW apt. F13 Now at
    Rochester, MN 55901 IBM card test division
    Check the luminance/chrominance [luma/chroma] circuitry that controls the picture output
    in black and white and color. I would check the 3.58 MHz crystal oscillator also on the video
    output as well. This things help with the color processing. Usually, it is an IC or integrated
    circuit (could even be a flatpack) that controls this or some discreet component like a transistor,
    resistor, or cap. that activates the IC).
    The problem can be open filter capacitors in the power supply.
    Excessive hash on the B+ busses can kill the color circuitry.

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  • From Charles Lucas@21:1/5 to All on Sun Aug 7 13:55:27 2022
    Both of these are some of the most interesting responses I have heard.
    Really great replies. Thanks for the insight. I was making the suggestion
    I made because we found the general vicinity of the problem, then measured voltages to hone down the specific line where the culprit was.

    The problem can be open filter capacitors in the power supply.
    Excessive hash on the B+ busses can kill the color circuitry.

    excellent suggestions and replies. Thank you.

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  • From Usenetist@21:1/5 to ohg...@gmail.com on Tue Jan 16 22:28:09 2024
    On 1/9/24 12:24, ohg...@gmail.com wrote:

    Hello! I have read all your posts and you are absolutely right. Unfortunately, there are always such people who qualify the helpers. Well, I also learned a lot from what was written here, at the hobby level I repair a VHS VCR, which also has no color.
    The type is AKAI VS-3. I repaired the servo part and the power part did not work. Now it starts, plays, spins. The head drum was also bad, so I put in a new original one. Now there is a picture, but it is black and white and jumps a little. I can't
    adjust the tape path any better. I would really appreciate it if you could advise me. I checked the video pcb, all12, pb12 are fine. Unfortunately, I don't have a test cassette, although I tried to make a color bar cassette and check it at the test
    points, but I didn't have much success.
    Thank you in advance for your help.

    Those old Akais had lots of electrolytic caps that get weak with age. Try heating the signal boards with a heat gun to see if the color returns. If it does, you're going to have to recap that unit if you intend to keep it.



    Can you explain the heat gun technique for bad caps... how does it work?

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  • From Chuck@21:1/5 to All on Wed Jan 17 15:19:51 2024
    On Tue, 16 Jan 2024 22:28:09 -0500, Usenetist <carg121@usenet.com>
    wrote:

    On 1/9/24 12:24, ohg...@gmail.com wrote:

    Hello! I have read all your posts and you are absolutely right. Unfortunately, there are always such people who qualify the helpers. Well, I also learned a lot from what was written here, at the hobby level I repair a VHS VCR, which also has no color.
    The type is AKAI VS-3. I repaired the servo part and the power part did not work. Now it starts, plays, spins. The head drum was also bad, so I put in a new original one. Now there is a picture, but it is black and white and jumps a little. I can't
    adjust the tape path any better. I would really appreciate it if you could advise me. I checked the video pcb, all12, pb12 are fine. Unfortunately, I don't have a test cassette, although I tried to make a color bar cassette and check it at the test
    points, but I didn't have much success.
    Thank you in advance for your help.

    Those old Akais had lots of electrolytic caps that get weak with age. Try heating the signal boards with a heat gun to see if the color returns. If it does, you're going to have to recap that unit if you intend to keep it.



    Can you explain the heat gun technique for bad caps... how does it work?
    When you heat up a bad cap, the ESR goes down and the capacitance goes
    up and sometimes the problem goes away. You then replace the cap you
    were heating when the symptom went away. I would suggest buying a
    cheap esr meter on EBay. It is a quicker and more certain way of
    finding bad capacitors.

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