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    TM5720-6792 has problems with projectors

    Discussion in 'Acer' started by snowbound, Jul 3, 2008.

  1. snowbound

    snowbound Notebook Guru

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    Anyone else have a TM5720-6792 hooked up to a video projector? Having problems with one when I try to use two different projectors an Optoma DLP and a Sanyo LCD model at 1024x768. Both of them when using the standard video cable between the laptop and the projector causes a shimmering or wave effect. It is noticable when one visits the Acer Canada website where the grey panel on the left hand side will wind up having horizontal "waves" rolling up the screen. Have tried different cable as well as two Tosh laptops and the TOSHs have no problem.

    Problem does not appear to occur when I hook up a 21" LG LCD to the VGA port. Acer already had it in for service once and simply "updated" the video chipset drivers and sent out a new ac adapter. AC adapter has no affect. Problem still occurs with or without it.

    Subsequent calls to them garnered a comment that the Acer was "tested" on a LCD monitor and a projector before they sent laptop back. Say that if the problem does not occur on monitor then I am SOL as the problem lies with how the projector is interpreting the video signal.

    :(
     
    snowbound, Jul 3, 2008
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  2. hoggie

    hoggie old boy

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    don't know if this will help but it sounds like a magnetic field affect.
    if you look on most cables there's a graphite suppressor or some kind of shielding.
    my monitor has one,playstation controls have them and the power cable to your laptop has one.
    try and get an old ps2 control pad and cut off the graphite block and place it near the projector first.if that doesn't work go the other end. near laptop/pc.
    my SVGA cable has one.

    EDIT: it has to go all the way around the cable.

    give it a try,
    Phil :D
     
    hoggie, Jul 3, 2008
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  3. hoggie

    hoggie old boy

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    types of graphite beads.
     

    Attached Files:

    hoggie, Jul 3, 2008
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  4. snowbound

    snowbound Notebook Guru

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    Why doesn't the 2 Toshiba's have the same problem as the Acer when using the same video cable?
     
    snowbound, Jul 4, 2008
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  5. hoggie

    hoggie old boy

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    could be build quality ?
    can you change the refresh rate on the acer ?
    see if that helps
     
    hoggie, Jul 4, 2008
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  6. bigozone

    bigozone JellyRoll touring now

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    different laptops...

    they may have better grounding or shielding or something like that...
     
    bigozone, Jul 4, 2008
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  7. snowbound

    snowbound Notebook Guru

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    Well looks like figured out what the problem is. There is a problem with the ground on the 5720 (not just this one) when using it with a projector. Tried the same two projectors on a friend's 5720 series laptop and same thing. Tried power coming off a UPS no diff. Happens at different places so it is not the power here.

    Had a power bar whose grounding plug was removed. Plugged the Acer into that and presto ... no more interference! There is something with this model when it is used with a projector that causes interference which is related to the grounds on the two devices. If one is using an external LCD monitor there is no problem.

    How the heck did Acer Canada supposedly test this laptop with a LCD monitor and projector and not see this problem?
     
    snowbound, Jul 4, 2008
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  8. hoggie

    hoggie old boy

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    so with no grounding your getting a field effect from the laptop. try and find some graphite to straighten out the field affect going to the projector. :D
     
    hoggie, Jul 5, 2008
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  9. bigozone

    bigozone JellyRoll touring now

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    i thought it sounded like a grounding issue.... as you can tell i've seen too may ground loop problems in my past...

    but Hoggie's suggestion is also a good one.... those little graphite loops/beads are used to trap interferance.....
     
    bigozone, Jul 5, 2008
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  10. snowbound

    snowbound Notebook Guru

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    If the laptop ac adapter is NOT grounded there is no interference on the projector. I initially tried a graphite core off another power adapter cord but that made no difference. Even though the Acer supplied replacement is from a different manufacturer it has graphite cores like the original adapter and this additional core made no difference on either.

    Only after pulling the ground pin off the spare power cord for the ac adapter for the Acer did that fix the problem when using it with a PROJECTOR.
     
    snowbound, Jul 5, 2008
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  11. hoggie

    hoggie old boy

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    nightmare: once again the coustmer sorts out Acer's problems for them.
     
    hoggie, Jul 5, 2008
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  12. bigozone

    bigozone JellyRoll touring now

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    sounds like the acer is picking up feedback from some other device thru the ground plug on the power cable....

    atleast the problem is resolved


    big0
     
    bigozone, Jul 5, 2008
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  13. snowbound

    snowbound Notebook Guru

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    Ya too bad I can't send Acer the bill for my time that I spent on this problem! :-(
     
    snowbound, Jul 5, 2008
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  14. hoggie

    hoggie old boy

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    just think, how much we could charge them with some of the fixes we have done on here. :cool:
     
    hoggie, Jul 7, 2008
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  15. bigozone

    bigozone JellyRoll touring now

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    hoggie,, i think they owe us each a new TOP OF THE LINE laptop...
    along with all support DOCs and files for all thier laptops... just for saving them the trouble :D
     
    bigozone, Jul 7, 2008
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