baird 42 flickering strobing wont start up

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • notallbad
    Badcaps Legend
    • Oct 2012
    • 1183
    • UK

    #41
    Re: baird 42 flickering strobing wont start up

    I had a PS b/d MLT668 rev1.5 with same symptoms, strobing backlight, replaced 5 caps and worked fine. The 5v stby, 12v and 24v rail voltages were unstable so may be a different fault causing the same symptom.

    I remember a couple of them being under a cage heatsink and the board looked very similar to yours. Used tweezers to hold cap in place through the cage, i.e did not remove cage heatsink, maybe I was just lucky to have easier access.
    Last edited by notallbad; 08-24-2013, 06:37 AM.

    Comment

    • wreksta
      Badcaps Veteran
      • Aug 2013
      • 508
      • england

      #42
      Re: baird 42 flickering strobing wont start up

      replaced all visual and one in left heatsink theres about 13-14 caps under right side heatsink

      I still haven't tested after replacing the 10uf 50v under left heatsink doing some more checks toms helping me

      Comment

      • wreksta
        Badcaps Veteran
        • Aug 2013
        • 508
        • england

        #43
        Re: baird 42 flickering strobing wont start up

        The 5v stby, 12v and 24v rail voltages were unstable so may be a different fault causing the same symptom.

        how to check this mate?

        Comment

        • tom66
          EVs Rule
          • Apr 2011
          • 32560
          • UK

          #44
          Re: baird 42 flickering strobing wont start up

          OK, that is PFC IC (http://www.ti.com/product/ucc28060). I would replace the cap near it. You can measure the resistance across the positive and negative of the cap -- power must be off while doing this.
          Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
          For service manual, schematic, boardview (board view), datasheet, cad - use our search.

          Comment

          • notallbad
            Badcaps Legend
            • Oct 2012
            • 1183
            • UK

            #45
            Re: baird 42 flickering strobing wont start up

            The caps I replaced, may differ on yours, were

            1000uF 10V
            470uf 25V (x2)
            470uF 35V (x2)

            If memory serves me well they were all located either near or under the cage next to the output connectors.
            Last edited by notallbad; 08-24-2013, 07:02 AM.

            Comment

            • wreksta
              Badcaps Veteran
              • Aug 2013
              • 508
              • england

              #46
              Re: baird 42 flickering strobing wont start up

              Originally posted by tom66
              OK, that is PFC IC (http://www.ti.com/product/ucc28060). I would replace the cap near it. You can measure the resistance across the positive and negative of the cap -- power must be off while doing this.
              tom that's the one I replaced mate so wht do yu think resolder heatsing back on screw mosfets back and test?????????

              Comment

              • wreksta
                Badcaps Veteran
                • Aug 2013
                • 508
                • england

                #47
                Re: baird 42 flickering strobing wont start up

                notallbad if what we doing fails il take a look and let you know what I got under that cage

                Comment

                • notallbad
                  Badcaps Legend
                  • Oct 2012
                  • 1183
                  • UK

                  #48
                  Re: baird 42 flickering strobing wont start up

                  Have you checked for any obviously bloated caps under the right heatsink?
                  A couple I replaced were bloated but a couple were not!

                  Comment

                  • tom66
                    EVs Rule
                    • Apr 2011
                    • 32560
                    • UK

                    #49
                    Re: baird 42 flickering strobing wont start up

                    Originally posted by wreksta
                    tom that's the one I replaced mate so wht do yu think resolder heatsing back on screw mosfets back and test?????????
                    Yep, I'd try it.
                    Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                    For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                    Comment

                    • wreksta
                      Badcaps Veteran
                      • Aug 2013
                      • 508
                      • england

                      #50
                      Re: baird 42 flickering strobing wont start up

                      Originally posted by notallbad
                      Have you checked for any obviously bloated caps under the right heatsink?
                      A couple I replaced were bloated but a couple were not!
                      nothing visual mate had a good look to lol
                      tom ttesting now will report back

                      Comment

                      • wreksta
                        Badcaps Veteran
                        • Aug 2013
                        • 508
                        • england

                        #51
                        Re: baird 42 flickering strobing wont start up

                        exactly the same tom any ideas

                        now if I remove the main av board power from the psu I don't get the clicking not sure hhow that works this connector is located on the right of the psu next to that on the left is all those caps under heatsink
                        this connector



                        anything else to check for
                        Last edited by wreksta; 08-24-2013, 07:41 AM.

                        Comment

                        • notallbad
                          Badcaps Legend
                          • Oct 2012
                          • 1183
                          • UK

                          #52
                          Re: baird 42 flickering strobing wont start up

                          With the Main a/v board disconnected the PS board is not fully running only provides 5v stby, 5v stby goes to main a/v, main a/v then sends on signal to PS b/d when remote control or power on button is pressed (not rocker on/off switch), the PS b/d then provides 12v to Main b/d and fully powers up.

                          So PS b/d switched on but disconnected from Main b/d will not be conclusive.

                          You could with a 1kOHM resistor jump the PS ON pin (not to be confused with the BL On pin) and 5v stby pin, with main A/V b/d connector disconnected.

                          Comment

                          • notallbad
                            Badcaps Legend
                            • Oct 2012
                            • 1183
                            • UK

                            #53
                            Re: baird 42 flickering strobing wont start up

                            Originally posted by notallbad
                            Do you have a DMM?

                            Measure voltages on the connector pins and note them here, remembering to number them and note the connector label.

                            Looks like the PS board connectors to the right of photo are from top to bottom

                            Main board
                            Audio (possibly) 4-pin (2 gnd and 2 might be 12,24 or 33v)
                            Inverter 10-pin (most likely 5 are gnd and 5 are 24v)

                            Refer to this thread for another Baird 42" (as suggested above):
                            https://www.badcaps.net/forum/showth...light=baird+42
                            Bump

                            The 4-pin connector could go to the inverter b/d and not be audio!
                            Last edited by notallbad; 08-24-2013, 07:53 AM.

                            Comment

                            • wreksta
                              Badcaps Veteran
                              • Aug 2013
                              • 508
                              • england

                              #54
                              Re: baird 42 flickering strobing wont start up

                              hi mate

                              how to measure that what should multi meter be set to and what pin where is this with all connectors disconnected except 2 pin power in and powered

                              Comment

                              • wreksta
                                Badcaps Veteran
                                • Aug 2013
                                • 508
                                • england

                                #55
                                Re: baird 42 flickering strobing wont start up

                                Originally posted by notallbad
                                Bump

                                The 4-pin connector could go to the inverter b/d and not be audio!
                                ]

                                4 pin is audio connector mate

                                could be those caps couldn't it under right heatsink

                                Comment

                                • notallbad
                                  Badcaps Legend
                                  • Oct 2012
                                  • 1183
                                  • UK

                                  #56
                                  Re: baird 42 flickering strobing wont start up

                                  To check voltages leave all the connectors in place.

                                  The black lead, Com, connected to the chassis, usually the screw holding the Ps b/d to the frame is fine.
                                  The red lead, Volt/Ohm, this probe connects to each pin, one at a time, be careful not to touch anything else with it whilst connected to the pin being measured.
                                  Set DMM to V DC 20, if it displays OL or 1. it means the voltage is greater than the DMM setting is set to so move it up to 200 in the same range i.e V DC.

                                  Never hesitate to ask if your unsure before doing something.

                                  Comment

                                  • notallbad
                                    Badcaps Legend
                                    • Oct 2012
                                    • 1183
                                    • UK

                                    #57
                                    Re: baird 42 flickering strobing wont start up

                                    Originally posted by wreksta
                                    ]

                                    4 pin is audio connector mate

                                    could be those caps couldn't it under right heatsink
                                    OK just wanted to be sure as can't see where it goes from the picture.

                                    Comment

                                    • notallbad
                                      Badcaps Legend
                                      • Oct 2012
                                      • 1183
                                      • UK

                                      #58
                                      Re: baird 42 flickering strobing wont start up

                                      I'm not trying to hijack this thread and by no means trying to suggest the problem is the same as I have experienced, just trying to help out and perhaps free a bit of Toms time by helping where I can.

                                      Tom is the best person for advise. I 'm always happy to help when and wherever poss.

                                      Comment

                                      • wreksta
                                        Badcaps Veteran
                                        • Aug 2013
                                        • 508
                                        • england

                                        #59
                                        Re: baird 42 flickering strobing wont start up

                                        Originally posted by notallbad
                                        To check voltages leave all the connectors in place.

                                        The black lead, Com, connected to the chassis, usually the screw holding the Ps b/d to the frame is fine.
                                        The red lead, Volt/Ohm, this probe connects to each pin, one at a time, be careful not to touch anything else with it whilst connected to the pin being measured.
                                        Set DMM to V DC 20, if it displays OL or 1. it means the voltage is greater than the DMM setting is set to so move it up to 200 in the same range i.e V DC.

                                        Never hesitate to ask if your unsure before doing something.
                                        mate I set my meter to 600vdc is this fine its only one of these
                                        http://www.petervis.com/electronics%...esistance.html

                                        Comment

                                        • notallbad
                                          Badcaps Legend
                                          • Oct 2012
                                          • 1183
                                          • UK

                                          #60
                                          Re: baird 42 flickering strobing wont start up

                                          600vdc will be too high and not give accurate enough readings, 20 will be fine, to the left of the OFF.

                                          Once you get a reading, say 4.6v for example, set the meter to the 600v setting and then see what reading you get then on your DMM. You will then see what I mean. The reading will probably say 3.8v or something lower than your original reading so less precise and be misleading when diagnosing.
                                          Last edited by notallbad; 08-24-2013, 08:18 AM.

                                          Comment

                                          Related Topics

                                          Collapse

                                          • reessi
                                            ACER BM320 Monitor - Horizonal Flickering Lines After a While
                                            by reessi
                                            Hello,

                                            The monitor started off showing flickering thin (1 pixel) lines horizontally every say 3mm..

                                            They are black on the right and gradually fade to nothing on the far left.
                                            They start either after 5 mins or up to 2 hours after so annoying for testing.
                                            They flicker continuously very fast! With a slight pause milli-second every second.

                                            Initially I cleaned the LVDS cable and connected to the T-Con and then it worked fine for 3 weeks but not sure if this was just co-incidence.

                                            I tested each half by removing the first the left flex from...
                                            06-03-2025, 09:58 AM
                                          • howardc64
                                            UN65TU7000 strobing / flicker
                                            by howardc64
                                            Good picture but has ~200Hz+ faint flicker/strobing over entire screen. Also has a single green vertical line. Can mask out t-con signals (2pins) to stop flicker/strobing but 1/12 of screen will be all colorful vertical lines (single green vertical line is in this section)

                                            Since can mask t-con signal to disable part of the screen and stop flicker/strobing. Obviously not backlight.

                                            Panel has 4x driver boards each responsible for 1/4 of the screen. 3 tabs on each board. Each tab responsible for 1/12 of the screen. the 2 outer most tabs has additional horizontal gate control...
                                            03-26-2023, 04:37 PM
                                          • zuehls
                                            samsung flashing/flickering/strobing
                                            by zuehls
                                            I have Samsung UN55ES6150 TS01 tv that has a backlight that flashes/flickers/strobes. I have disconnected the cable between main board and power supply and the backlight stops flashing/flickering/strobing. I checked the voltage on power supply (BN44-00503a) CNL802 pin 4 (R-) and pin 6 (l+) and both are 141v each. It is also steady. If I reattach the cable between main board and power supply and plug in the tv it is steady and good at 141v for about 5-7 seconds and then the screen starts flickering/flashing/strobing and the voltage starts bouncing between 138-142. What is correct voltages on CNL802?...
                                            05-11-2020, 03:34 PM
                                          • DrvLikHell
                                            Fixing an I-Inc IF281D for the 3rd time, now with added flickering!
                                            by DrvLikHell
                                            Hello everybody! It's been nine years and I'm back again with the same monitor that several people here helped me fix back then. The first time, I replaced two caps as was recommended here and the original problem was solved. Then it started acting up a few years later and I came back for a parts list and replaced a few more caps (I didn't make a post about that and don't remember which ones), and again the problem was solved. This time, however, I'm not sure if it's caps.

                                            The monitor stays on but certain colors will flicker. Generally it's darker colors like dark greys or dark blues,...
                                            07-05-2024, 02:54 AM
                                          • Jaysean
                                            Acer VN7-591G-70RT Display Flickering
                                            by Jaysean
                                            Hello Badcaps coummunity hope you all are having a bless day,

                                            Hope I didn't post it wrong kinda new at forum site rules and tradition

                                            So I'm dealing with screen flickering problem on my laptop.

                                            I'm not quite sure if it's the display cable or the screen itself that's causing the issue,

                                            so I'm turning to you all wonderful expert on Badcaps for some guidance. Your help is much appreciated!

                                            [Screen Flickering](https://i.imgur.com/xK9vHqc.mp4)
                                            [HDMI port to external display seem to work be working](https://i.imgur.com/snSC24e...
                                            10-27-2023, 10:22 AM
                                          • Loading...
                                          • No more items.
                                          Working...