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    InFocus Projector

    alright when i baught this projector it would not power on. when power was applied it would just click. then whan the power was pulled off it would click again. im guessing from a short. anyway i tested all of the caps and 2 were obviously way out of its recommended esr value. i replaced those 2 caps and since there wasnt a ton of other caps on there i went and replaced the rest of them as well. i finished the job today and went to plug it in. the indicator lights come on and then a whistle starts to come from the unit. the lamp then powers on but acts weird as the brightness of the light changes in pace with the intensity of the whistle?...any ideas guys?

    #2
    Re: InFocus Projector

    Originally posted by shibby_cbs View Post
    alright when i baught this projector it would not power on. when power was applied it would just click. then whan the power was pulled off it would click again. im guessing from a short. anyway i tested all of the caps and 2 were obviously way out of its recommended esr value. i replaced those 2 caps and since there wasnt a ton of other caps on there i went and replaced the rest of them as well. i finished the job today and went to plug it in. the indicator lights come on and then a whistle starts to come from the unit. the lamp then powers on but acts weird as the brightness of the light changes in pace with the intensity of the whistle?...any ideas guys?
    1. You were very wise to replace all the caps. A lot of people try to 'cheap out' and only replace a few.

    2. What brand and series of caps did you use? That whistling could be due to a cap out of spec.

    3. Use a tube like the center of a roll of towels to localize the source of the whistling.

    4. A picture is worth a thousand words. Note the link in my signature for tips on getting good ones.

    5. On either end of the ZXCVBNM<>? row of keys are 'Shift' keys. Learn to use them, please.

    PlainBill
    For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.

    Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.

    Comment


      #3
      Re: InFocus Projector

      these are the three caps that i used

      CAP 1
      http://search.digikey.com/scripts/Dk...ds=493-1525-ND

      CAP 2
      http://search.digikey.com/scripts/Dk...words=P5138-ND

      CAP 3
      http://search.digikey.com/scripts/Dk...ords=P11685-ND



      So are you saying the whisteling would be coming from the specific cap?

      Does cap series matter. If so in what way

      Comment


        #4
        Re: InFocus Projector

        Yes, capacitor series does matter.

        For example, If you replace a low ESR capacitor with a general purpose non-low-ESR capacitor you can get problems. Or it may work, but only last 3 months.

        Please write a list of what capacitors you removed, what brand and series they are (or what markings were on them)
        "Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
        -David VanHorn

        Comment


          #5
          Re: InFocus Projector

          Originally posted by Agent24 View Post
          Yes, capacitor series does matter.

          For example, If you replace a low ESR capacitor with a general purpose non-low-ESR capacitor you can get problems. Or it may work, but only last 3 months.

          Please write a list of what capacitors you removed, what brand and series they are (or what markings were on them)
          CAP 1
          16v 680uf LXV (M)105c 2(2) 7c

          CAP 2
          16v 100uf SMG (M)85c

          CAP 3
          450v 270uf CE 85c LS (M) nichicon

          the large cap was the only one that was labeled with a brand name so i assume the rest were of the same brand

          Comment


            #6
            Re: InFocus Projector

            The HE's are very good as is the ED series.

            The M's are only 85°F caps and I don't like their (lack of) specs for SMPS use. I would suggest Panasonic FM's in 120uF@16v or 100uF@25v or the Nichicon HE's in 100uF@25v.

            I would look to the CAP 2 near the big cap as a probable cause of the squealing. It's very likely not low enough in ESR for the switcher.

            Toast

            "the large cap was the only one that was labeled with a brand name so i assume the rest were of the same brand"

            FYI: The others had a little shield emblem which is United Chemi-con.
            Last edited by Toasty; 11-21-2010, 12:13 AM.
            veritas odium parit

            Comment


              #7
              Re: InFocus Projector

              Now knowing that they were SMG's with an outrageously high ESR of 3.3Ω, I'm not sure that the M's were any worse.

              HE's are a good match to LXV.
              veritas odium parit

              Comment


                #8
                Re: InFocus Projector

                interesting....the little ones were the ones causing the problem in the first place. ill get some new (better) ones on order and let ya know how it goes. when i put the paper towel roll over the board to see where the squeeling was coming from it seemed to be coming from the big cap. but that little one is pretty close to it so who knows

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