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    Acer AL1717, slow to turn on

    We have two AL1717 LCD monitors purchased at the same time which have spent their entire lives in the same machine room.

    One has been on for years, mostly in standby mode (no video from the server it is always attached to), and this one works great.

    The other was used for fixing whatever machine in that room broke, and was usually off with no power, being on no more than a month total since it was made. This is the one that is now failing.

    When power is applied and the power button pressed nothing happens at first. If the power button is pressed repeatedly, over 30 seconds or a minute, the power LED starts to blink, but nothing shows up on the display. Eventually the LED goes solid and the "ACER" screen comes up. After that it works normally.

    Have any of you ever serviced one of these, or a closely related model, with these symptoms? Other than the usual "check for bulging/leaking capacitors" what should I be looking for? Since it works, eventually, I'm guessing none of the fuses are blown and some capacitor in the power supply is failing, taking a long time to charge up and provide adequate power to the logic and inverter sections.

    The one thing about the environment that has changed recently is that a slipping belt on the AC unit was recently replaced, so the room is now a few degrees cooler than it was a couple of months ago. This display was moved to a warmer room, and is warming up for a couple of hours before trying it there, just because I'm curious if it will work better at a higher temperature. It still needs to be fixed though, because it needs to work in the machine room.

    #2
    Re: Acer AL1717, slow to turn on

    Unless the monitor is unplugged from the wall outlets, the power supply will be running 24/7 as long as it is plugged in, it is an always on power supply. So, yes look at the caps first.
    There are at least 2 versions of this model:
    http://s807.photobucket.com/user/bud...?sort=3&page=1
    http://s807.photobucket.com/user/bud...?sort=3&page=1
    Never stop learning
    Basic LCD TV and Monitor troubleshooting guides.
    http://www.badcaps.net/forum/showthr...956#post305956

    Voltage Regulator (LDO) testing:
    http://www.badcaps.net/forum/showthr...999#post300999

    Inverter testing using old CFL:
    http://www.badcaps.net/forum/showthr...er+testing+cfl

    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
    http://s807.photobucket.com/user/budm/library/

    TV Factory reset codes listing:
    http://www.badcaps.net/forum/showthread.php?t=24809

    Comment


      #3
      Re: Acer AL1717, slow to turn on

      Originally posted by budm View Post
      Unless the monitor is unplugged from the wall outlets, the power supply will be running 24/7 as long as it is plugged in, it is an always on power supply.
      It was on a power strip, when it was off, the power strip was also off.

      Originally posted by budm View Post
      So, yes look at the caps first.
      There are at least 2 versions of this model:
      http://s807.photobucket.com/user/bud...?sort=3&page=1
      http://s807.photobucket.com/user/bud...?sort=3&page=1
      Ours are version "AL1717 ab", and there is a small blue plastic jack right next to the VGA connector that isn't visible in the pictures you linked.

      I just noticed that when it is in the "blinking" phase it cannot be turned off with the power switch. Once the power LED goes solid green the power switch starts working again. Once it finally gets into that state it seems to be OK going forward. Unplug the monitor once it is on, plug it in again quickly, and it works fine. Wait 30 seconds and it is still good, but wait 5 minutes, and it is back to square one.

      This kind of reminds me of PC power supplies I have seen where the standby power circuit was failing. When attached to a PC that would result in a computer that wouldn't turn on reliably, but would run forever once it was finally on.

      Thanks.

      Comment


        #4
        Re: Acer AL1717, slow to turn on

        It sounds like bad start up cap (22~47uF 50V typical) in the primary side.
        Never stop learning
        Basic LCD TV and Monitor troubleshooting guides.
        http://www.badcaps.net/forum/showthr...956#post305956

        Voltage Regulator (LDO) testing:
        http://www.badcaps.net/forum/showthr...999#post300999

        Inverter testing using old CFL:
        http://www.badcaps.net/forum/showthr...er+testing+cfl

        Tear down pictures : Hit the ">" Show Albums and stories" on the left side
        http://s807.photobucket.com/user/budm/library/

        TV Factory reset codes listing:
        http://www.badcaps.net/forum/showthread.php?t=24809

        Comment


          #5
          Re: Acer AL1717, slow to turn on

          ESR of electrolytic capacitors decreases with rising temperature. So if you have a device that starts working or starts working correctly after a "warm-up" period it is probably a capacitor.

          Comment


            #6
            Re: Acer AL1717, slow to turn on

            Seen plenty of these Acer AL1717 monitors. There are also many versions of the same model (AL1717, AL1717B, AL1717EE, AL1717p, AL1717t, AL1717v, AL1717x, etc). Externally may looks the same but quite often the boards inside are different. The most common source of problems for these monitors is always badcaps, especially at the inverter section (e.g. banding or flickering) and secondary side power filter (e.g. cannot power up or blinking LED indicator). Thus just open it up and check those capacitors in the sections mentioned. Also look at the big electrolytic capacitor (rated 450VDC) on the primary side. Often a dying capacitor there can cause startup problems (e.g. takes time to power up, or very difficult to power up)...

            Comment


              #7
              Re: Acer AL1717, slow to turn on

              Originally posted by lexwalker View Post
              The most common source of problems for these monitors is always badcaps, especially at the inverter section (e.g. banding or flickering) and secondary side power filter (e.g. cannot power up or blinking LED indicator). Thus just open it up and check those capacitors in the sections mentioned. Also look at the big electrolytic capacitor (rated 450VDC) on the primary side. Often a dying capacitor there can cause startup problems (e.g. takes time to power up, or very difficult to power up)...
              Spot on. It will definitely be capacitors causing this issue.
              Originally posted by PeteS in CA
              Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
              A working TV? How boring!

              Comment


                #8
                Re: Acer AL1717, slow to turn on

                Took it apart today. It has a PTB-1648 board, dated "9/28'05". No camera at work but found a picture on the web that looks just like the power board, right down to the date and other markings.

                There are 3 swollen caps as marked in red in the lower right quadrant of the picture. They are not fully vented, but there is just a touch of brown crap leaked from the vent seams. The big power supply cap looks OK. C824 and C822 (the two that are together) are both CapXon 1000uF 10V, C823 (the one in the lower right corner) has a big blob of the rubbery gunk on the side that has its specifications, so it is hard to read, but it also seems to be 1000uF, from the few digits sticking out of the blob, but I'm not sure at what voltage. Since it is the same size as the other 2 failed ones most likely it is also 10V. All the other caps on the board look OK. Mostly they are CapXon with a couple of Su'scon.
                Attached Files

                Comment


                  #9
                  Re: Acer AL1717, slow to turn on

                  Replace all secondary side caps. Su'scon like to dry out without bloating. Monitor should work fine then.
                  Originally posted by PeteS in CA
                  Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
                  A working TV? How boring!

                  Comment


                    #10
                    Re: Acer AL1717, slow to turn on

                    replace the 2 small caps bottom-center and all 5 lower-right.

                    Comment


                      #11
                      Re: Acer AL1717, slow to turn on

                      Originally posted by stj View Post
                      replace the 2 small caps bottom-center and all 5 lower-right.
                      Did that, it works now.

                      Thanks.

                      Comment

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