Daewoo Model DP-42SM won't turn on

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  • tieny
    Badcaps Veteran
    • Feb 2012
    • 478
    • USA

    #21
    Re: Daewoo Model DP-42SM won't turn on

    theres no PWR_CTRL labeled on the board as stated in the manual, but tracing the connector back to part of the main board, there is one named "PSM_ON" would that be the one? There are still no voltages on the pins except for STBY5V and LED_P.

    STBY5V - 5.09V
    GND - 0V
    3rd pin - 0V
    PSM_ON - 0V
    LED_P - 4.75V

    I found that when I unplugged the 5 pin connector from the board, the TV won't power on (Red LED goes off).

    What specifically are we looking for? What does it mean when theres no voltages on ON/OFF?
    Attached Files
    Last edited by tieny; 03-27-2012, 08:37 AM.

    Comment

    • tieny
      Badcaps Veteran
      • Feb 2012
      • 478
      • USA

      #22
      Re: Daewoo Model DP-42SM won't turn on

      Checking around the components near the 5 pin connector, I found an Oscillating voltage on one end of this resistor and the other end measures 101v. The range of oscillation seems to decreasure over a period of time. Not sure if its relevant?
      Attached Files

      Comment

      • tom66
        EVs Rule
        • Apr 2011
        • 32560
        • UK

        #23
        Re: Daewoo Model DP-42SM won't turn on

        The oscillating voltage may be important later.

        The lack of PSM on probably means a problem with the main board. Check all the voltage regulators there.
        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

        • selldoor
          Slow Learner
          • Dec 2010
          • 7870

          #24
          Re: Daewoo Model DP-42SM won't turn on

          Did I understand you to say you had checked 3 fuses?
          If so can I assume these are the 3 glass tube fuses?

          There are other fuses mentioned in the manual as fusible resistors - did you check them.

          Also in Post5 picture five there is a fuse F801 and possibly another at FU801 did you check these.

          There may be more but I dont have time to look, tried searching the manual but didnt turn up anything, so over to you. May be some on the backs of the boards as well.
          Please upload pictures using attachment function when ask for help on the repair
          http://www.badcaps.net/forum/showthread.php?t=39740

          Comment

          • tieny
            Badcaps Veteran
            • Feb 2012
            • 478
            • USA

            #25
            Re: Daewoo Model DP-42SM won't turn on

            Ok I think I might of short circuited something. While measuring the component circled in the picture I got readings of

            pin1: -49V
            pin2: -54.7V
            pin3: Reading out of range?

            I accidently slipped while changing my multimeter and touched pins 2 and 3 and then there was a small spark =(

            Now the red LED power light won't come on.

            I checked standby voltages and it is now zero. Checked the fuses and they still seem good, so I'm sure something got fryed.

            I rechecked the component that I shorted and got measurements.

            pin1: -49V
            pin2: -54.7V
            pin3: oscillating between 0 to -30 V

            I searched up the component below it and it seems to be a power rectifier diode? The picture is in the previous post,the 1st pin of it was also reading out of range, guessing voltage > 600 and the 2nd pin read 54.7V


            the power rectifier diode I measured again after the spark
            pin1: oscillating between 0 to -30 V
            pin2: 54.7v

            What was shorted?
            Attached Files

            Comment

            • tieny
              Badcaps Veteran
              • Feb 2012
              • 478
              • USA

              #26
              Re: Daewoo Model DP-42SM won't turn on

              Eh I'm still stuck and don't know what I'm looking for. I thinking I should just buy another psu and just start swapping components.

              http://www.ebay.com/itm/DAEWOO-DP-42...item20c31e1c26

              Comment

              • tom66
                EVs Rule
                • Apr 2011
                • 32560
                • UK

                #27
                Re: Daewoo Model DP-42SM won't turn on

                Originally posted by tieny
                Eh I'm still stuck and don't know what I'm looking for. I thinking I should just buy another psu and just start swapping components.

                http://www.ebay.com/itm/DAEWOO-DP-42...item20c31e1c26
                It depends on what the TV is worth.

                Remember it's 480p. Not even 720p or HD. So it's not worth much. I picked up a nearly working 480p LG Plasma 42" for £2.20. Heck, I have trouble selling 720p plasmas now...
                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

                • tieny
                  Badcaps Veteran
                  • Feb 2012
                  • 478
                  • USA

                  #28
                  Re: Daewoo Model DP-42SM won't turn on

                  Well, I'm trying to get a working 42" tv for my room but my last 2 projects became a bust and I'm still stuck on my little 23 "

                  My question is, what could of cause the tv being stuck on standby and not powering on? Defective regulator, transformer, capacitor before I accidentally short circuited it?

                  Comment

                  • tom66
                    EVs Rule
                    • Apr 2011
                    • 32560
                    • UK

                    #29
                    Re: Daewoo Model DP-42SM won't turn on

                    Originally posted by tieny
                    My question is, what could of cause the tv being stuck on standby and not powering on? Defective regulator, transformer, capacitor before I accidentally short circuited it?
                    Probably a main board problem.
                    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

                    • tieny
                      Badcaps Veteran
                      • Feb 2012
                      • 478
                      • USA

                      #30
                      Re: Daewoo Model DP-42SM won't turn on

                      Main board problem? What should i check for on the main board? Seems it wont send the signal to bring it out from standby?

                      Comment

                      • tom66
                        EVs Rule
                        • Apr 2011
                        • 32560
                        • UK

                        #31
                        Re: Daewoo Model DP-42SM won't turn on

                        Originally posted by tieny
                        Main board problem? What should i check for on the main board? Seems it wont send the signal to bring it out from standby?
                        Check the voltage regulators and fuses (if any are present.)
                        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

                        • tieny
                          Badcaps Veteran
                          • Feb 2012
                          • 478
                          • USA

                          #32
                          Re: Daewoo Model DP-42SM won't turn on

                          I'm working on another daewoo model now (Don't know how to find the shorted component from the previous one). This is the same model with the same problem but silghtly different chassis.

                          Here are photos of the board with with PSM_ON pin connector. Don't seem to see any fuses, but what is a voltage regulator? Can you point it out from the photos shown, Which one is it, and how do I know if its defective?

                          I just now noticed that if i press the menu buttons or any other buttons, the relay clicks, and the red LED power button turns green but still no picture. Hadn't noticed the buttons that was on the other side under the panel til now.
                          Attached Files

                          Comment

                          • tibimakai
                            Badcaps Legend
                            • Jan 2012
                            • 3680
                            • USA

                            #33
                            Re: Daewoo Model DP-42SM won't turn on

                            IC610, IC611, etc.

                            Comment

                            • tom66
                              EVs Rule
                              • Apr 2011
                              • 32560
                              • UK

                              #34
                              Re: Daewoo Model DP-42SM won't turn on

                              Check each pin on each device which looks like the ones tibimakai suggested.
                              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

                              • jeffescortlx
                                Member
                                • May 2011
                                • 40

                                #35
                                Re: Daewoo Model DP-42SM won't turn on

                                The power button is just a Standby/Off switch.

                                To turn the TV on, with out the remote, you just need to push one of the other buttons, like volume.
                                There is nothing wrong with your power supply.

                                This is why you have no video:
                                https://www.badcaps.net/forum/showth...619#post249619
                                Last edited by jeffescortlx; 07-05-2012, 06:24 PM.

                                Comment

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