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AE300 flicker adjustment changing over time

Discussion in 'Projectors, Screens & Video Processors' started by snocrash, Jan 28, 2003.

  1. snocrash

    snocrash
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    G'day all,

    Hey, I've noticed something that I'm not terribly happy with.

    When my AE300 had 4 or 5 hours on it... I did the service menu flick adjustment, and as per everyone else's experience you can almost 100% eliminate red and blue flicker but not green...

    Now at around 40 hours... I've gone back in and noticed that I can't get the blue flicker as good as I used to... (used to be as flicker free as red) -- So now red is almost perfect.. normal, blue has a slight twitch to it... and green is normal.

    Whats the story... I know a fair bit about these beast's... and I can't work it out... It's either the globe aging, or the mains power (very unlikely).

    Anyhow... just thought some others would share their views on this one.
     
  2. snocrash

    snocrash
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    OK, I've just done some followup testing on this matter and you're just going to freak-out...

    It appears that the particular mains power-socket makes a material difference to the flicker adjustment. I've just tried two different sockets in the same room and without a shadow of a doubt seen differences in the flicker on blue and green.

    This may mean that there is noise being induced on the line, which would also indicate that the power-supply inside the AE300 isn't particularly well designed.

    Anyhow... an interesting observation all the same especially being almost scientific in its replication.
     
  3. Harb

    Harb
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    G'day Snocrash,
    Yep I to have noticed Flicker Adjustments moving about just slightly......
    But if left for sometime it seems to correct itself......May be Mains Freq related.
    I have also noticed that the adjustment tends to change from one source input to another.
    As soon as I have some time, I will monitor the mains freq (Auto Plot a Chart) for a day or two and compare that to the PJ performance.
    I also have some very Trick Tektronix gear in one off my OB Vans that I am just busting to put some signals into the AE300 and see if I can shed some light on this Artifact Business........
    I must try and order the WS manual again and see if the english version is available yet.

    Despite any shortcomings the panny may have (and there are very few) in my opinion we still have the pick of the bunch, In the pricerange we are in, and above a bit as well!!!


    Cheers
    John:cool:
     
  4. Harb

    Harb
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    Snocrash,
    Do you have more than 1 Phase in your home?
    is it posible you are shifting to a different phase?

    Anyway, the fact that you have discovered this, means there may be a cure to eleiminate the flicker all together....

    I have a 5KVA extreme Isolation sytem in my workshop and a matching power Conditioning System.......so I can Supply the HT with Clean Stable Power.....I will try and let you know the result.
    May take a day or two as the HT and the WS are in diferent Locals.

    Good Work.
    John
     
  5. snocrash

    snocrash
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    What's you're thoughts of the AE300 picking up all sorts of RF and EMI because it isn't earthed ? (using the jap power cord)

    By the way, I must say that I don't think that the flicker adj is source dependant at all. The scan-line artifacts are definately source dependant, but not the service mode flicker... (I perform the flicker adj with no source)
     
  6. Harb

    Harb
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    Yes sorry I should say that it is the scanlines, that are the thing that I am seeing the shift in as a result of changing sources......
    As far as the earthing of the PJ is concerned.........it is indeed posible I supose.
    Mine is not earthed........and runs at 110v via a stepdown TX.
    I can hardly wait till the warranty runs out so I can do some real experiments with this beast.
    I'm sure there is more in there just waiting to get out!

    John
     
  7. snocrash

    snocrash
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    Yes, I'm three-phase here... I have a UPS here which is basically mains (phase) independant when fired off DC so I'll have a fart around with that.

    I'm much more likely to sway towards the interference possibility from the un-earthedness. I might just run a single earth wire from one of the ceiling mount threads (which are earthed) to the 240 earth ... what do you think ?
    :)
     
  8. Harb

    Harb
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    Well I guess thats one way............be careful, but I guess you know that.

    We Go to great lenghts to make sure that all Related Equipment is running on the same Phase, ie all Electronics on Phase 1 , All Lights on Phase 2 , All Aircon and sundry on phase 3 etc.....
    I have had various instances where interference has been caused buy earth loops and phase imbalances.
    If all the gear is on the one phase I'd say ok, But if any gear at all is hooked to the PJ input and that gearis on a different phase.......problems may arise.
    Also all Earths must come back to a common point be really sure.

    John
     
  9. Harb

    Harb
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    Sorry I forgot to ask,
    Have you tried this with all the inputs disconected with only the power lead hooked up?

    John
     
  10. snocrash

    snocrash
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    Two things effect the LCD panel flicker... having the unit earthed and also the mains frequency. All RCA inputs on the AE300 are connected to the earth pin. So a simple way to ensure the thing is earthed is have the projector plugged into your computer as almost all PC's run earthed powersupply's.

    The other thing I've noticed is that the panel-flicker changes as the mains frequency does. 50Hz is the worst with 60 being slightly better. The best is at 57.5Hz, Blue and Red are zero flicker while Green is imperceptible unless you are having the screen image hitting your peripheral vision and even then the other two people in the room couldn't pick it. A side effect is almost total elimination of scanline effects with a 625i and 625p input.

    The reasoning behind this could be many things, but primarily I'd say that the 'beat' frequency of any resonant harmonics gets to a point where the "service adjustments" are able to eliminate them.

    The final word on having stuff 'in phase' ... I don't see how, being a totally rectified DC device, the projector would be effected by being out of mains phase with any other device .. just a thought.
     
  11. Harb

    Harb
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    As a mater of interest,
    I have done some tests with the Service Mode Flicker Adjustment and found the following.
    The input mode selected does have a bearing on the flicker adjustment.
    Whatever input mode you were on when you go to the service mode changes very dramatically effects the result you get when you adjust...........
    On PC mode I can Stop the green flicker altogether, yet on S-video input, I can't even get close to stopping the flicker on the green channel.
    I don't think the mains Freq is the answer, as most devices these days are not as dependant on Mains dirived freq standards.
    For those that are curious about that, The mains Freq changes throughout the day somewhat.
    Down at the power station, the people down there know exactly how many cycles are in a 24 hour period, they aim to hit on that number every 24 hours ( The freq is governed by the speed at which the generators rotate, which can be altered slightly)
    Back when Electric clocks where introduced it was not unusual to see the clocks running fast or slow during the 24 hour period as the Power station made up or lost a "few" cycles..........
    This problem has now been adressed in the clock world anyway, with the use of Crystals and ocillators which "lock" the freq.
    But most other Equipment does not have to provide such an accrurate account of the time, so are mostly unaffected by the problem........PJ's would be one of them.
    I think it is more likely that the flicker adjustment is affected by earthing or some other factor introduced via the mains and its inputs...........
    I will experiment further............................................

    John
     

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