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Sony E400 Monitor failing

Discussion in 'Electronic Repair' started by James Watkins, Feb 20, 2004.

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  1. Greetings,

    I have a Sony E400 19" Trinitron Computer monitor which is just over 3 years
    old and gradually failing. For approximately the last year, the black level
    has been slowly creeping up to the point where the picture looks washed out.
    The problem is now so bad that with a black screen, you can see the scan
    retrace lines. This is extremely disappointing because the monitor cost
    over $600.00 when I bought it and, I simply can not afford to replace it at
    this time. I have seen other posts complaining of this problem so it is not
    uncommon, however I have yet to find the fix. I have been told that some
    inadequate components in the power supply which change value with time are
    the likely problem, but no one seems to be able to say which specific
    components are to blame. Surely someone has more information on this. If I
    knew which components were the source of the problem, I would simply order
    new parts and replace them. I sure would appreciate any help anyone could
    offer.

    Thank You,

    --Jim
     
  2. Jerry G.

    Jerry G. Guest

    The reason why there are no specifics, is that there are too many
    combinations of component failure to be specific that can cause levels in
    the pictures to change.

    A common cause of this in many TV sets and monitors are failing electrolytic
    caps. Then there are the main components such as resistors, semiconductors,
    and whatever. To test the caps an ESR meter is the best tool for this. It is
    best to start in a logical area, which would be in the video path that is
    common to all 3 colour channels which would most likely be in the CRT bias
    supply circuits for the video amp drivers, and CRT electron-gun.

    I have seen in many cases, the high voltage multiplier going defective, and
    thus allowing the screen voltage to go too high. I have also seen the CRT
    itself going defective, and cause levels to change. There are circuits that
    generate blanking pulses. These should also be verified.

    As a temporary fix, you can open the monitor and see if there is a screen
    control on the back of the flyback assy. If so, you can turn it down a crack
    and see if this helps. The control should be marked "screen" or "G2". There
    is normally also a set of focus controls in most of these models. One of
    them is for V and the other for H axis. Don't touch these unless you want to
    refocus the beam. When moving the screen adjustment, the colour tracking may
    also be effected. Then the tracking set-up may have to be touched up.
    Depending on the monitor model, the factory service interface will be
    required.

    The bottom line, is that the monitor would have to be properly checked. The
    service manual, knowledge of the monitor, and the proper test equipment
    would be required to service your monitor, if the basic checks do not locate
    the fault. If you call Sony, they can recommend the authorized service rep
    near to you who can properly do this type of work.

    As for a computer monitor, I would not invest too much money in to it. The
    prices have dropped dramatically over the last few years. You can get a very
    descent 19 inch CRT monitor now for about $250 to $300 US average. If you
    look at the LCD types, they have become very good over the last few years,
    and the prices have dropped by a lot.

    The LCD monitor has many advantages over the CRT type, except for doing
    critical photo work, where very precise low grey level resolution is
    required, and where a very high contrast ratio is required.

    --

    Greetings,

    Jerry Greenberg GLG Technologies GLG
    =========================================
    WebPage http://www.zoom-one.com
    Electronics http://www.zoom-one.com/electron.htm
    =========================================


    Greetings,

    I have a Sony E400 19" Trinitron Computer monitor which is just over 3 years
    old and gradually failing. For approximately the last year, the black level
    has been slowly creeping up to the point where the picture looks washed out.
    The problem is now so bad that with a black screen, you can see the scan
    retrace lines. This is extremely disappointing because the monitor cost
    over $600.00 when I bought it and, I simply can not afford to replace it at
    this time. I have seen other posts complaining of this problem so it is not
    uncommon, however I have yet to find the fix. I have been told that some
    inadequate components in the power supply which change value with time are
    the likely problem, but no one seems to be able to say which specific
    components are to blame. Surely someone has more information on this. If I
    knew which components were the source of the problem, I would simply order
    new parts and replace them. I sure would appreciate any help anyone could
    offer.

    Thank You,

    --Jim
     
  3. John Gill

    John Gill Guest

    James:
    I would start by checking the heater voltage on the CRT pins.
    I have seen some Sony monitors where the electrolytic capacitor in
    the heater suppy voltage would gradually go bad, reducing the voltage
    at the heater pins, and causing the picture to get darker.
    Remove the shield over the circuit board and measure the voltage
    on the heater pins of the CRT socket. You should get 6.3 volts (DC).
    If you measure a lot less, trace the circuit down into the main
    board and look for weak capacitors in the circuit. 470 Uf at 16 volts
    is a common capacitor vaule found in heater circuits.
    Hope this helps....
    John
     
  4. Thanks for the info Jerry. Well, this is disappointing. I do have the
    service manual for the monitor but there appears to be no adjustment for the
    screen. It looks like I spent $620.00 plus 8.25% California sales tax for a
    monitor which provided about 2 years of good service. Sony charges a flat
    rate of $175 plus 8.25% California sales tax to repair it regardless of what
    the problem is. It would make better sense to buy a new monitor. I had
    hoped to purchase a LCD monitor whenever I replaced this one, but I
    absolutely can't afford to do that at the moment since I am unemployed at
    this time. For that matter I really can't afford to replace the monitor
    with a CRT even if I could get one for $100.00 bucks. What I could afford
    would be $20.00 bucks or less worth of parts. I guess I am stuck watching
    this monitor get gradually worse over time. I appreciate your effort to
    help. I can tell you that I will never purchase another Sony monitor. To
    have such an expensive item go bad in such short time is simply unacceptable
    yet apparently common.

    Best regards,

    --Jim
     
  5. James Sweet

    James Sweet Guest


    Well even if there was an adjustment, adjusting it wouldn't fix the problem
    as something has failed. Why not take it to an indepenant shop and have them
    take a look at it? Might be a bit cheaper, the E400 is still a nice monitor.
     
  6. Bob Kos

    Bob Kos Guest

    It would???? That's a nice monitor. You're not going to buy anything like
    that for $200. I recommend that you set it aside till you have the
    resources to have it properly repaired. Don't hack it by going in and
    tweaking the adjustments.

    Go pick up a used 17" as a stop gap. They're cheap and you don't have money
    right now, so it's a good match. Get the Sony fixed when you're in a better
    spot. It's worth it.



    I had
     
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