Benq Q9T3 FP937s-D does not switch on

Collapse
X
Collapse
+ More Options
Posts
 
  • Time
  • Show
Clear All
new posts
  • tacosgr
    New Member
    • Jan 2012
    • 7

    #1

    Benq Q9T3 FP937s-D does not switch on

    Hello to all and happy new year from Greece,

    It is my first post in this super forum so mind me if i make any mistakes.
    As you can see in the pictures the filter cap C605 blown and for sure C703 & C704 are bulged.
    The monitor was working fine untill some flickering a blackout and power on again from the electric company.
    The main fuse 2A @ 250V is not blown.
    Can anyone give me some tips.(I know for sure i have to check rect bridge BD601 and Mosfet Q601).
    Attached Files
  • PlainBill
    Badcaps Legend
    • Feb 2009
    • 7034
    • USA

    #2
    Re: Benq Q9T3 FP937s-D does not switch on

    You seem to be well on the way to having it sorted. I'd suggest doing the complete job.

    1. Test the bridge rectifier and power FET. Inspect the thermistor for signs of damage - it took a current surge. Replace these components if damaged.

    2. Replace all electrolytic caps, even the small (<100 uF) ones with name brand low ESR caps.

    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

    • Krankshaft
      Badcaps Legend
      • Jan 2007
      • 2328
      • USA

      #3
      Re: Benq Q9T3 FP937s-D does not switch on

      Benq boards are also known for dry joints in the inverter section that will take out the driver transistors if left unchecked.

      Resolder the inverter transformer pins, the gray tombstone caps in between the driver transistors and the two inductors in the inverter section. I have almost always found cracks on the gray tombstone caps when by the time the drivers had finally failed.

      Then look over the inverter section for any other suspect joints and touch them up as well.
      Elements of the past and the future combining to make something not quite as good as either.

      Comment

      • cpp
        New Member
        • Dec 2009
        • 9

        #4
        Re: Benq Q9T3 FP937s-D does not switch on

        primary side is probably dead, check the mosfet , the little ic near (1200ap40) and replace the big cap ,
        check too the two big resistors near

        you can desolder the outputs of the transformer for easy repair and mesure on the primary side.

        then , replace all caps on secondary side ,and resolder all pins on the two inverter transformers.

        sorry for my english.

        Comment

        • retiredcaps
          Badcaps Legend
          • Apr 2010
          • 9271

          #5
          Re: Benq Q9T3 FP937s-D does not switch on

          There also might be a picofuse protecting the inverter section. Check that as well.
          --- begin sig file ---

          If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.

          We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.

          Please do not post inline and offsite as they slow down the loading of pages.

          --- end sig file ---

          Comment

          • tacosgr
            New Member
            • Jan 2012
            • 7

            #6
            Re: Benq Q9T3 FP937s-D does not switch on

            Thank you PlainBill , Krankshaft , cpp and retiredcaps for all your advises and your immediate answers.
            In order to update my situation , i made the orders for all the components you suggested exept the pico fuse on inverter side that is ok.
            Awaiting for the components to arrive and i will post back the results
            Thank you all for your support .

            Comment

            • tacosgr
              New Member
              • Jan 2012
              • 7

              #7
              Re: Benq Q9T3 FP937s-D does not switch on

              Hi to all again ,
              I would like to thank you once more for all your advices and update this thread.
              Finally today my components arrived and started the repair .
              Main filter cap replaced , rect.diode checked foun ok , mosfet checked found ok , all elec. capasitors replaced (just in case).
              The monitor was re-assembled again plugged in and is working fine (untill now)
              I think the repair was succesful , so consider this thread as solved.

              Comment

              Related Topics

              Collapse

              • Document Archive
                Acer Switch Switch V 10 SW5-017P Hybrid (2-in-1) V 10 Specification for Upgrade or Repair
                by Document Archive
                This specification for the Acer Switch Switch V 10 SW5-017P Hybrid (2-in-1) can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the Switch V 10 SW5-017P boardview and Switch V 10 SW5-017P schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification,...
                09-06-2024, 05:30 AM
              • Natob82
                Micro Momentary Push Switch?
                by Natob82
                Great to be here! I'm a newbie here trying to find a "micro", momentary push switch to repair a Sony "clamshell" video walkman. This micro switch has long since discontinued by Sony, however I hope there are third-party switches of the same size and functionality that I might be able to source to play the same role. The purpose of this switch is to tell the video walkman that the user has activated the mechanical tape eject button, turning that physical action into an electronic signal that tells the tape transport mechanism to open so one can load or eject a video tape. I...
                12-21-2022, 05:22 AM
              • grimacelord
                NEC TurboExpress On/Off Power Switch Replacement Help
                by grimacelord
                Hello,

                I've been working on a NEC TurboExpress and I accidentally got the plastic inside the power ON/OFF switch too hot while doing other repairs and melted it. At first, it would still power on when sliding the switch, but you had to really press inward while sliding to get it to work.

                I removed the switch component and tried to gently melt the plastic back so it would work more reliably and all I managed to do was make it worse.

                I need to find a replacement On/OFF switch for this, but having some trouble figuring out which kind of switch I need....
                11-09-2023, 09:49 AM
              • SluggerB
                Help making a switch work the opposite way with a relay
                by SluggerB
                I have a very small float switch, I'm using in a very small tank. It only fits in one way. Link https://www.amazon.com/uxcell-Switch.../dp/B07DZ1J2GB

                I want the switch to be open when the water is high, and closed when the water is low. Unfortunately it works the opposite. And since this switch is designed to be underwater, it's all sealed up, there is no taking it apart or hacking it up.

                It will be driving a water pump, basic idea, when the water is low, switch closes, which turns on water pump, when enough water is in the tank, float switch floats,...
                02-07-2025, 07:57 PM
              • sam_sam_sam
                Modifying a 4 Position Universal Rotary Cam Changeover Switch LW26-20 for more cams
                by sam_sam_sam
                Panel Mount 4 Position 8 terminals Universal Rotary Cam Changeover Switch LW26-20 20A
                ( needs more cam circuits for the machine to work correctly again )

                https://www.ebay.com/itm/275321870186

                To
                3 Position 16 Terminals Universal Rotary Cam Changeover Switch LW28-20 20A
                ( not 4 positions but the right amount of cams circuits )

                https://www.ebay.com/itm/274660439950

                I going to take the 4 position cams selector switch and remove the cams that are on it and remove the cams off of the 3 position selector switch and swap them around...
                03-18-2023, 05:12 PM
              • Loading...
              • No more items.
              Working...