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Vizio VO42L FHDTV10A will not turn on...

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    #1

    Vizio VO42L FHDTV10A will not turn on...

    My Vizio 42" will not turn on. I looked through some of the existing issues individuals have had on the same TV.

    I did notice that 2 of the 4 MOSFETs on the Master Inverter board measure less than 8.6Kohms (1 almost 0ohms and the other like 2.2Kohms). I removed those 2 mosfets and confirmed that they were OK. It appears my BD9897FS is no good on the Master Inverter board.

    However, when I disconnect everything from the power supply board, only having the AC plugged in, I measure 0v at all the 5V, 12v, 24, PS_on, etc. I checked the main fuse on the power supply board an dit appears good when I measured it with the meter. I did a visual inspection of the caps, and they too appear in good condition (majority are Nichicon and 1 or 2 are Rubycon).

    In the following https://www.badcaps.net/forum/showth...inverter+board, it appeared the individual ha dthe same problem as me, but they were able to measure the 5V (see there post #9).

    I guess I',m not sure where to start looking. I checked the 2 fuses on the main board and they measured OK. ANy more pointers would be great.

    Thanks in advance for any help.
    Tags: None
    #2
    Re: Vizio VO42L FHDTV10A will not turn on...

    Originally posted by richr69 View Post
    My Vizio 42" will not turn on. I looked through some of the existing issues individuals have had on the same TV.

    I did notice that 2 of the 4 MOSFETs on the Master Inverter board measure less than 8.6Kohms (1 almost 0ohms and the other like 2.2Kohms). I removed those 2 mosfets and confirmed that they were OK. It appears my BD9897FS is no good on the Master Inverter board.

    However, when I disconnect everything from the power supply board, only having the AC plugged in, I measure 0v at all the 5V, 12v, 24, PS_on, etc. I checked the main fuse on the power supply board an dit appears good when I measured it with the meter. I did a visual inspection of the caps, and they too appear in good condition (majority are Nichicon and 1 or 2 are Rubycon).

    In the following https://www.badcaps.net/forum/showth...inverter+board, it appeared the individual ha dthe same problem as me, but they were able to measure the 5V (see there post #9).

    I guess I',m not sure where to start looking. I checked the 2 fuses on the main board and they measured OK. ANy more pointers would be great.

    Thanks in advance for any help.
    Pictures always help. I HATE searching to threads looking for a picture of a power supply that might be the same.

    Most TV power supplies are dual supplies. There is a small 'standby' section that provides either 5V or 12V. This is always live if the power cord is plugged in. The second section is the main supply, and is switched on by the PS_ON line.

    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: Vizio VO42L FHDTV10A will not turn on...

      You found a bad chip on a board. Now, it may sound simple enough that maybe that is the only problem that you have. These sets sometimes check all other boards before turning on other voltages. If this chip is shorted, maybe it's telling the rest of the set not to supply more voltages. If you already located a bad chip, unless something went terribly wrong or a fuse blew, this is the only cause of your symptoms. Here is another thread where we had talked about a similar problem.

      https://www.badcaps.net/forum/showth...974#post129974
      The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS

      Comment

        #4
        Re: Vizio VO42L FHDTV10A will not turn on...

        I have attached some pictures of the power supply, main board, and the Master Inverter boards.
        Attached Files

        Comment

          #5
          Re: Vizio VO42L FHDTV10A will not turn on...

          Originally posted by richr69 View Post
          I have attached some pictures of the power supply, main board, and the Master Inverter boards.
          It helps if you keep the pictures as close to 2000 x 2000 pixels as possible. That way I can read the labels on the connectors. I get tired of asking for clear pictures.

          This is a dual power supply with PFC front end. In the picture of the entire supply the smaller transformer to the lower right is for the standby supply. Hook the supply up to the main board and the AC cable.

          Points to check. What is the voltage across the large (150uF, 450V) cap? Do you get any readings between any of the pins on the connector at the lower right?

          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

            #6
            Re: Vizio VO42L FHDTV10A will not turn on...

            The voltage across the cap is 164.4-VDC. I measure 0-VDC on all the pins on the lower right connector.

            Comment

              #7
              Re: Vizio VO42L FHDTV10A will not turn on...

              Originally posted by richr69 View Post
              The voltage across the cap is 164.4-VDC. I measure 0-VDC on all the pins on the lower right connector.

              That really helps to narrow the problem down. The standby supply isn't coming up. Now to figure out why.

              On the picture of the bottom side of the board there is an eight pin IC near the top center of the board. It is slightly above and to the left of the transformer I have identified as providing standby power. What is the part number of that IC?

              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

                #8
                Re: Vizio VO42L FHDTV10A will not turn on...

                PlainBill - thank you for your assistance.

                I have attached additional pictures with labels. I hope this helps.
                Attached Files

                Comment

                  #9
                  Re: Vizio VO42L FHDTV10A will not turn on...

                  Originally posted by richr69 View Post
                  PlainBill - thank you for your assistance.

                  I have attached additional pictures with labels. I hope this helps.
                  Not really - but it's not your fault. I can't find any references to a 2A07D12.

                  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

                    #10
                    Re: Vizio VO42L FHDTV10A will not turn on...

                    PlainBill - What were your thoughts regarding the chip? Where were you going with it? What made you suspect or think of looking into that particular chip?

                    I tried searching various places on th einternet, but I can not seem to find any information of that chip. I cam across the service manual, but it only lists the parts for the main board. It actually lists the power supply as DPS-283AP L-F, but the actual power supply I have indicates DPS-260HP-1. The power supply is manufactured by Delta Electronics.

                    Comment

                      #11
                      Re: Vizio VO42L FHDTV10A will not turn on...

                      Originally posted by richr69 View Post
                      PlainBill - What were your thoughts regarding the chip? Where were you going with it? What made you suspect or think of looking into that particular chip?

                      I tried searching various places on th einternet, but I can not seem to find any information of that chip. I cam across the service manual, but it only lists the parts for the main board. It actually lists the power supply as DPS-283AP L-F, but the actual power supply I have indicates DPS-260HP-1. The power supply is manufactured by Delta Electronics.
                      You have listed 5 ICs on the board. They are DAS001, which appears to be a legitimate number, but I have been unable to discern it's function, in large part due to a lack of interest - it's associated with L6562D, which is a PFC controller from ST Microelectronics. The DLA001D (actually an L6598) is an SMPS controller, and is obviously for the main supply. The 358A is actually an LM358A, a dual op-amp.

                      The only one I have been unable to identify is the 2A07D12. By it's physical location and some clues from the picture, that chip is the SMPS controller. With the datasheet for that IC I MIGHT be able to figure out if it is defective, or if the problem is elsewhere.

                      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

                        #12
                        Re: Vizio VO42L FHDTV10A will not turn on...

                        I'm currently waiting for the chip that was bad on my Master Inverter board. I guess I'll see what happens after I fix my inverter board and connect everything back up.

                        The 2A07D12 IC has a logo on it, which looks like 6 concentric circles. I done a search but could not identify the logo. I tried various sights which list IC manufacture logs, but no luck.
                        Attached Files

                        Comment

                          #13
                          Re: Vizio VO42L FHDTV10A will not turn on...

                          I finally received the Inverter Board chip and hopefully I will be able to work on it this weekend. My question, given my power supply issue, once I get the Inverter board fixed, should I connect everything back and see if the TV powers up (assuming that maybe the Inverter board was the issue and not the power supply)?

                          Comment

                            #14
                            Re: Vizio VO42L FHDTV10A will not turn on...

                            Originally posted by richr69 View Post
                            I finally received the Inverter Board chip and hopefully I will be able to work on it this weekend. My question, given my power supply issue, once I get the Inverter board fixed, should I connect everything back and see if the TV powers up (assuming that maybe the Inverter board was the issue and not the power supply)?
                            Well, if my tooth hurts me and I get a headache, I wont go to a brain surgeon but a dentist. I think your power problem is due to the inverter problem. If after the chip is replaced you find that the problem still exists, at least you know you fixed one definite problem that would keep it from working. From my estimations though, this should fix your problem.
                            The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS

                            Comment

                              #15
                              Re: Vizio VO42L FHDTV10A will not turn on...

                              Well I installed/soldered the BD9897FS chip onto the Slave Inverter board. Made sure that all 4 MOSFETs now read 8.6Kohms across the Drain and Source. Connected everything back up and hit th epower button... nothing.

                              I guess I'm back to the power supply. At least I have the Inverter board fixed.

                              I had no luck trying to identify the chip on the power supply. Maybe I'll have to find a replacement power supply board.

                              Comment

                                #16
                                Re: Vizio VO42L FHDTV10A will not turn on...

                                Good job on that chip. It's not the easiest repair. The pads sometimes want to come up a little. Did you check all of the diodes on the power board yet?
                                The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS

                                Comment

                                  #17
                                  Re: Vizio VO42L FHDTV10A will not turn on...

                                  Having a good magnifying glass, a fine tip on the soldering iron and a steady hand helps alot

                                  I'll try the diodes next, which I haven't checked yet - thanks.

                                  Comment

                                    #18
                                    Re: Vizio VO42L FHDTV10A will not turn on...

                                    I have spent time trying to track down the 2A07D12 5531 8-pin chip.

                                    I came across a website of someone looking for a very similar part (2A06810 5522), and it was suggested that the part number was most likely Fuji Electronics FA5522.

                                    I thought I try searching for Fuji Electronics FA5531 and sure enough I found some information. I also found that ON Semiconductor equivalent is NCP1207.

                                    In past posts this is the chip which PlainBill could not identify. I'm hoping this information will help me get further into figuring out what is wrong with the PSU (assuming that FA5531 is infact the correct chip).
                                    Attached Files

                                    Comment

                                      #19
                                      Re: Vizio VO42L FHDTV10A will not turn on...

                                      Originally posted by richr69 View Post
                                      I have spent time trying to track down the 2A07D12 5531 8-pin chip.

                                      I came across a website of someone looking for a very similar part (2A06810 5522), and it was suggested that the part number was most likely Fuji Electronics FA5522.

                                      I thought I try searching for Fuji Electronics FA5531 and sure enough I found some information. I also found that ON Semiconductor equivalent is NCP1207.

                                      In past posts this is the chip which PlainBill could not identify. I'm hoping this information will help me get further into figuring out what is wrong with the PSU (assuming that FA5531 is infact the correct chip).
                                      It appears to be a match; at least I didn't see any obvious discrepancies.

                                      Using the negative lead of the 150uF, 450 V cap as the ground point, with power connected carefully measure the voltage at pins 1-6 and 8 of the SMPS controller. I am particularly interested in the voltage at pins 4, 6, and 8. This IC uses a internal current source to provide start up power. Historically, these ICs have a higher failure rate than those which use a resistor (or resistors) to drop the voltage to the IC. Also, with power off, what is the value of R907?

                                      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

                                        #20
                                        Re: Vizio VO42L FHDTV10A will not turn on...

                                        PlainBill, I finally had a chance to measure the voltages and the value of the resistor. Pin 6 measures 8.4v, pin 8 measures 13.3v, and all other pins measure 0v. For the heck of it I also measured pin 7 which indicated 0.1v.

                                        Also, resistor R907 is a 100Kohms that measured 99.4Kohms.

                                        Comment

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