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Sony E400 Monitor - Black level adjust?

Discussion in 'Electronic Repair' started by Peter V Rawlings, Nov 27, 2005.

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  1. I've had this 19" FD Trinitron-based unit for around 5 years. Quite early
    on, the black became greyer and flyback-like white diagonal lines started to
    become visible. In truth, the situation has 'flattened out' now, but I'm
    sure this is a burn-in issue that once adjusted back is likely to go the
    distance - yes?

    I realise this is not uncommon for the E400 - where the on-screen set-up
    does not allow you to turn the brightness down any further - clearly there
    is early life drift in one or more of the HT/EHT components. :-(

    Is there a simple one-touch adjust inside that is going to let me bring down
    the black level without losing geometry or have other set-up interactions?

    If it is straightforward, an ident/location of the trimmer would be greatly
    appreciated.

    Cheers,

    Pete.
     
  2. Ray L. Volts

    Ray L. Volts Guest

    The flyback should have two controls on it: focus and screen
    You can try to reduce the screen voltage to get rid of those retrace lines.
    There are a number of freeware programs that generate patterns to help
    adjust monitors. Using a contrast/resolution or greyscale tracking pattern
    may help you back off the screen control to your liking. You may need to
    bring up the contrast after this.
    If you turn the focus control by accident you'll have to correct it,
    preferrably using a dot pattern -- adjust for sharpest center dot.
    These controls are simple enough to change back if they affect geometry or
    you don't like the results for other reasons.
    Just be careful with the screen control and don't turn it the wrong way or
    the unit might go into HV shutdown. Even if it does, it shouldn't blow
    parts, but be on the safe side anyway -- slowly move the control to see
    which direction is the right one.
     
  3. Ray L. Volts

    Ray L. Volts Guest

    uhh.. actually, you might find 3 flyback controls.. at any rate, the screen
    control is the relevant one... er, unless a change in it adversely alters
    focus..
     
  4. .............good stuff trimmed!........
    Thanks Ray - the ball-park, rule-of-thumb advice puts me in the picture.
    I'll just hang on a bit and see if anyone has got specific insight into the
    vagaries of the E400!

    Cheers,

    Pete.
     
  5. Guest

    You need the Sony DAS, digital alignment software, and interface to to
    any kind of screen/G2 adjustment on that monitor. In fact you need the
    software and interface to actually troubleshoot the real failure and
    complete any repair.

    It could be a corrupted eeprom, bad process ic (common), or a simply
    weak picture tube. The process ic is suppose to properly compensate
    for the weak picture tube and fine adjust the screen and bias controls
    to keep a good picture, but it doesn't work that way.

    There has been a hack to compensate for the real problem as it is not
    cost effective to buy the DAS kit for just one monitor repair. Check
    the google archive and recent posting.
     
  6. Many thanks for the input, dk.

    Although I haven't taken the case off, I did get the impression that this
    one is a bit hi-tech for a newb!

    I'm not good at googling and would appreciate any relevant links to the
    troubleshoot and repair. I appreciate this might be beyond your scope.

    If the tweak is not a low-tech one, I'll start saving for a 19" LCD now!
    :-(

    Many Thanks,

    Pete.
     
  7. ampdoc

    ampdoc Guest

    Warning - HIGH VOLTAGE in this circuit -typically 1200V!!! Any work you
    perform is AT YOUR OWN RISK, I take no respnsibility whatsoever. This post
    is for information only.

    If this monitor is built on the same design as the IBM/sony P260 and Compaq
    P1100, sony G1 Chassis, you will find the screen voltage sourced from a
    second transformer. It does not come from the flyback/lopt. There is a
    transistor on the CRT board and the screen voltage is dynamic, regulated by
    a PWM like control/feedback loop. Two things can be done to correct the
    problem- Either invest in the DAS software to realign the unit, or fool the
    feedback loop and make the unit regulate itself. R457 and R459 on the A
    Board are your target.(CRT PCB) In my monitor I took a standalone HV
    potentiometer out of an older monitor and paralelled it across the 2
    resistors (they are in series), so that I had an actual adjustment I could
    use. It has worked very well, though you could do the same with fixed
    resistors as well, if adjustment is not a concern.

    I have a schematic for the G1 chassis but it's big, I can send it if you
    can take 4M e-mail attachments.
     
  8. Okay JH - thanks for the 'health warning' - understood! ;-)

    If I had sight of the circuit info you suspect is applicable, I reckon I can
    verify whether it matches-up.

    The file size should not be an issue this end - depending on its format!

    Just remove the stuff in capitals from the email address.

    Thanks for the help.

    Cheers,

    Pete.


    .............
     
  9. Sky

    Sky Guest


  10. Cheers Sky! I'll try to get my head around it later this week. Whenever -
    I'll let you know! :)

    Thanks,

    Pete.

    PS: Thanks to others for encouragement too! :-O "Be seeing you!"
     
  11. Hi Sky et al,

    My worst fears: It seems the E400 does not share the architecture of your
    excellent reference and their example pics - hence, without any applicable
    assembly/circuit info for this one, I'm going to have to put my shades on
    'til the EHT gives up! :-(

    Just out of interest: The construction differed once the rearmost shield
    was removed. Instead of showing the back of the required board, it revealed
    the CRT connector board only - all the other parts were screened by a
    second shield. :-( Different enough for me to think - "this is different!"
    :-/

    Many thanks for the G500 info link though.

    Cheers,

    Pete.

    PS any other offerings for this brightness fix for my E400? :-(
     
  12. You might try tweaking the G2 control slightly. It'll be on the side of
    the flyback, along with one (or possibly two) Focus controls.

    Isaac
     
  13. Wayne

    Wayne Guest

    The hack is to replace R053 on the CRT PCB with a resistor of slightly
    lower value. Google for 'R053 F99 monitor'

    Wayne
     
  14. Ray L. Volts

    Ray L. Volts Guest

    That's what I first thought, but the others that corrected me are right.
    Sony adjustments are performed with proprietary software and special
    hookups. When I mentioned the flyback controls earlier in the thread, I was
    thinking back to the CTX PR960F I had which used the 19" FD Trinitron tube.
    The resistor hack repeatedly mentioned in this thread seems to work for most
    people.
     
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