Polaroid 32in LCD FLU-3232 no power

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • DoctorWedgeworth
    Senior Member
    • Jul 2012
    • 65
    • England

    #1

    Polaroid 32in LCD FLU-3232 no power

    Hi,

    I bought this yesterday to mess with. There's no lights, no buzzing, nothing when it's plugged in. I'm a little too amateur to use a multimeter when it's plugged into the mains so I've not tried.

    The PSU board looks burnt out. The metal shield above it was brown, as is the underside of the board. Some of it was dust, and some came off with electrical cleaner, but not all. A lot of the solder on the bottom looks discoloured too.

    The top of the board is here, and the bottom is here. That large capacitor on the top (labelled 25/105/U40) has both solder joints discoloured (the other bad joints looked to be from the heatsink?) so I was wondering if I should try to replace it. The top of it wasn't domed, but the plastic above the top was (chipping the plastic off shows the metal top to be flat).

    I've got a few questions:
    • Can anyone help me identify that capacitor?
    • Do some of the tracks look broken? Should I try running a bit of solder along them?
    • Is there a fuse on the board I should replace? Sorry for how amateur this is, but does anyone know where it is?
    • Short of replacing the board, does anyone have any other suggestions to help me get started?


    I'm very new to this, so please be gentle.
  • tom66
    EVs Rule
    • Apr 2011
    • 32560
    • UK

    #2
    Re: Polaroid 32in LCD FLU-3232 no power

    It's fairly common for the plastic dome to bulge on those bigger caps, but unless the metal vent underneath is bulged, the cap is fine.

    There's little danger in testing the secondary side of the power supply. The secondary is the side which is plugged into the main board and other boards in the TV. The highest voltage you'll find there is about 24V, which isn't even enough to tingle. On the other hand, the primary side (mains side) has a large 400V or 450V capacitor which can be substantially charged, so this presents a potential shock hazard. In addition, be careful not to touch any heatsinks with power applied, as they are potentially live.

    My tips:
    - Unplug the TV
    - Test the main fuse using your DMM. Use the 200 ohm range; you should see close to zero ohms. If the reading doesn't change (stays at what it is with the probes not touching), then the fuse is blown.
    - If the fuse is blown your prime suspects are the bridge rectifier and power MOSFET, but the fuse can sometimes fail without due cause (simply thermal stress or by being underated.)
    - If the fuse is okay you need to look elsewhere and begin testing the secondary output voltages, for example the standby.
    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

    • DoctorWedgeworth
      Senior Member
      • Jul 2012
      • 65
      • England

      #3
      Re: Polaroid 32in LCD FLU-3232 no power

      Thanks a lot for the help so far. The plug fuse is fine (I tried it in a laptop charger and the light came on).

      I tried resoldering that big capacitor back in place and running some solder along of the broken tracks but it hasn't made a difference. There's just no response.

      Sorry for knowing so little here, but how do I know which side is the 24v side? Do you mean just check some capacitors on the main board? Or is there a side of the power board I should be checking? Those transformers and the big capacitors scare me.

      Also, how long should I be waiting for the capacitors to dissipate or whatever after I unplug it before I can mess again? It's worth mentioning as well that the air vent under the power board is scorched brown.

      Comment

      • tom66
        EVs Rule
        • Apr 2011
        • 32560
        • UK

        #4
        Re: Polaroid 32in LCD FLU-3232 no power

        These are genuinely rubbish TVs in my opinion. Was the main board and PSU in a metal cage? That will slowly but surely cook the power supply caps.

        Anyway, there are more fuses than the plug fuse. I think this might be a fuse, highlighted with the red arrow. Can you get a closer pic around here?

        The secondary/24V (safe) side is highlighted below in the image using the blue ring.

        For the secondary side you don't need to worry about the capacitors as they don't have a sufficient voltage to cause harm. Touching the 450V capacitor will hurt a lot though, so just keep away from it. Usually it will discharge in 30 seconds after power is unplugged but if there's a problem on the board somewhere it will sometimes not discharge. I have touched one before accidentally, it is just a sharp, short shock but it can make you throw the power supply out of your hands by reflex action!
        Attached Files
        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

          #5
          Re: Polaroid 32in LCD FLU-3232 no power

          Hi - can you perhaps redo the pictures with more light ( But not flash)
          Ideally they should look like this.
          We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

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

          Examples of what is needed
          https://www.badcaps.net/forum/attach...1&d=1290283049

          https://www.badcaps.net/forum/attach...7&d=1280167246
          Please upload pictures using attachment function when ask for help on the repair
          http://www.badcaps.net/forum/showthread.php?t=39740

          Comment

          • DoctorWedgeworth
            Senior Member
            • Jul 2012
            • 65
            • England

            #6
            Re: Polaroid 32in LCD FLU-3232 no power

            Thanks for the response, and sorry if my original pictures were a bit poor. I've uploaded several more - one of the back of the TV with everything screwed in, one of the top of the main board, one of the top of the PSU screwed in place, one of the fuse, one of the connections on the safe side of the PSU and then one of the bottom of the PSU.

            I think you're right about it being a fuse. It says T5AH/250V next to it, but when I search for that I can only find the ceramic fuses. Any idea where I can get one from? Also, would it be a really stupid idea to solder across the fuse to bypass it, just to confirm that the blown fuse is the problem? I realise that could cause other components to blow, but it looks like the air vent was just covered up at some point. Not that I know what I'm talking about.

            You were right about it being inside a metal cage. I think I can screw it back together without the cage in place, should I? I know it's a bad TV, it's just a learning experience for me.

            Thanks for your responses.

            Comment

            • DoctorWedgeworth
              Senior Member
              • Jul 2012
              • 65
              • England

              #7
              Re: Polaroid 32in LCD FLU-3232 no power

              Sorry I've just realised the pictures never upload. I've sat waiting for the upload screen for 10 minutes but there was no progress bar or indication that anything had happened. I know you requested that I post them here, but I think my battery will go dead before that completes so I've uploaded another imgur album

              Comment

              • DoctorWedgeworth
                Senior Member
                • Jul 2012
                • 65
                • England

                #8
                Re: Polaroid 32in LCD FLU-3232 no power

                One other thing I forgot to mention is that I used the multimeter on that labelled socket on the "safe" side of the PSU. It was labelled 24V so I used 40V DC on the multimeter and placed one pin on inside the plug where it was labelled 24V, and the other on the part labelled earth, and there was no response. I tried both ways round, and I also tried AC. It looks like it's completely dead at that side.

                Comment

                • tom66
                  EVs Rule
                  • Apr 2011
                  • 32560
                  • UK

                  #9
                  Re: Polaroid 32in LCD FLU-3232 no power

                  These TVs are okay when working, but the build quality is atrocious. In other words, I would be highly disappointed if I paid good money for something like this.

                  T5A/5H is probably a ceramic fuse. 5A, time delay, 250V.

                  DO NOT bypass the fuse as it will likely result in a substantial "bang" if there continues to be a fault condition. This is what happens when a fake fuse is installed in a TV (molten glass was flung across my workshop, both the plug fuse and the main breaker also tripped), now imagine no fuse at all...

                  Do you see a pin marked 5V or STBY or ST5V? If you don't list all the pin labels...
                  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

                  • DoctorWedgeworth
                    Senior Member
                    • Jul 2012
                    • 65
                    • England

                    #10
                    Re: Polaroid 32in LCD FLU-3232 no power

                    I think the pin labels are shown on the photo (uploaded afterwards), but yeah I do. The pins are, from top to bottom, 24V, GND, GND GND, GND, 12V, 5V, 5VSB, STB.

                    Do I have to desolder the fuse to get the cover off it so I can see it? Or is prizing with a flat head screwdriver okay? There's a photo of that too in the album above. Sorry for failing to attach them on the same.

                    Comment

                    • tom66
                      EVs Rule
                      • Apr 2011
                      • 32560
                      • UK

                      #11
                      Re: Polaroid 32in LCD FLU-3232 no power

                      Ugh, this is one thing I hate about them, too cheap to afford a socket. You can test it with your digital multimeter.

                      Unplug the board, wait 30 seconds, set meter to 400 ohm scale,

                      Test across the marked position. (The upper two terminals, you can see the isolation gap. Not the lower two ones (admittedly my diagram is a little unclear.))

                      If the fuse is good, you will see close to zero ohms (0 to 2 ohms.)

                      If the fuse is bad, the meter reading will not change or it will be very high.

                      Also check if your meter is functioning correctly by touching the probes together. You should see close to 0 ohms as well.
                      Attached Files
                      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

                        #12
                        Re: Polaroid 32in LCD FLU-3232 no power

                        OK - I think this is going to be a learning experience for us all. Do you want to say which town you are in or would you rather not? (just for advising re parts)
                        Two easy rules Measuring resistance = Power off
                        Measuring Voltage = Power on
                        Have you tested the fuse? - power off meter on ohms 200 one probe on each fuse contact should read 1 ohm or less - same as touching the probes together.

                        I have marked up the back of the board - red joint needs resoldering
                        Cant tell what has happened on Pink sections - can you tell if they are ok or post close ups. Pink block again check this out is it touching - should it?
                        Attached Files
                        Please upload pictures using attachment function when ask for help on the repair
                        http://www.badcaps.net/forum/showthread.php?t=39740

                        Comment

                        • DoctorWedgeworth
                          Senior Member
                          • Jul 2012
                          • 65
                          • England

                          #13
                          Re: Polaroid 32in LCD FLU-3232 no power

                          Thanks. If I set to 400ohms and don't touch it says 0L. If I touch the probes it says 00.6 (sometimes goes up and down .1). If I test across the two solder joints for the fuse (that's not where you marked, I assume that was deliberate?) I get 0L. The two red lines you drew, am I right to assume you wanted me to test just above each of them (and not underneath or below them)? Either way, it settles on 00.5 to 00.6.

                          The TV is a bit shoddy and I probably overpaid for it (£20 broken), but I'd pay more than that for a half day electronics course with test equipment so it's worth it

                          Thanks a lot for your help so far, I really appreciate it.

                          Comment

                          • tom66
                            EVs Rule
                            • Apr 2011
                            • 32560
                            • UK

                            #14
                            Re: Polaroid 32in LCD FLU-3232 no power

                            £20 ain't bad for a 32" actually.

                            Just to be sure were you testing across these two terminals? (clearer diagram this time.)
                            Attached Files
                            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

                            • DoctorWedgeworth
                              Senior Member
                              • Jul 2012
                              • 65
                              • England

                              #15
                              Re: Polaroid 32in LCD FLU-3232 no power

                              selldoor, thanks again. I'm in Rossendale, Lancashire. I don't mind waiting a few days for parts if they're reasonable off the Internet. I tried the multimeter (with 400ohms) for tom66 and reported it above.

                              Thanks for highlighting the solder joints. I'll redo the red one next time I heat the iron up. The left pink one is here - that one is actually my fault, I tried resoldering it with my shoddy cheap soldering iron (the tip doesn't get hot, only the side) and I couldn't get it all up. I don't think it bridged the gap there, but I'll heat it up again and take it further away. Sorry for the poor focus of this one, my phone just refused to do better.

                              The bottom right one is here, and the yellow one you highlighted is here.

                              Once again, sorry for the quality of these photos. For some reason, once I get close to the board the phone just drops focus completely. If you download the raw one of the board from imgur you might be able to zoom quite well.

                              Comment

                              • tom66
                                EVs Rule
                                • Apr 2011
                                • 32560
                                • UK

                                #16
                                Re: Polaroid 32in LCD FLU-3232 no power

                                Farnell now have free delivery with no minimum order, for all customers. eBay sellers reselling Farnell components at ridiculous prices are doomed.
                                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

                                • DoctorWedgeworth
                                  Senior Member
                                  • Jul 2012
                                  • 65
                                  • England

                                  #17
                                  Re: Polaroid 32in LCD FLU-3232 no power

                                  tom66 - I thought that's what you meant, thanks those two terminals aren't from the bottom of the fuse, is that okay? I tested those two last time, and I get:
                                  No connection - 0L.
                                  Touching two prongs together - 00.5 (but fluctuates 00.4 to 00.6 between tests)
                                  Touching across terminals - 00.6 (but fluctuations 00.5 to 00.7 between tests)
                                  Touching across the two solder joints from the fuse itself: 0L.

                                  So it looks to go up very slightly. Note though that I just removed one side of the fuse so it's not connected, and then retested and it did exactly the same thing. I assume this means the fuse is blown?

                                  Comment

                                  • DoctorWedgeworth
                                    Senior Member
                                    • Jul 2012
                                    • 65
                                    • England

                                    #18
                                    Re: Polaroid 32in LCD FLU-3232 no power

                                    Is this the fuse I need? http://uk.farnell.com/littelfuse/046...a/dp/1817215RL

                                    Comment

                                    • DoctorWedgeworth
                                      Senior Member
                                      • Jul 2012
                                      • 65
                                      • England

                                      #19
                                      Re: Polaroid 32in LCD FLU-3232 no power

                                      Also, once I take the fuse holder fully out (not going to do it tonight), how do I either get the fuse out to replace it, or find a replacement socket to put the new one in?

                                      Comment

                                      • tom66
                                        EVs Rule
                                        • Apr 2011
                                        • 32560
                                        • UK

                                        #20
                                        Re: Polaroid 32in LCD FLU-3232 no power

                                        Looks like this is getting tricky. I want you to test across the fuse itself; perhaps it would be better to remove the fuse entirely (desolder both sides) and test it out of circuit. It's kind of difficult to work out where the fuse is on that PCB, but I thought it was where I marked it.

                                        The fuse you need is here http://uk.farnell.com/littelfuse/032...-5a/dp/1596794.
                                        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

                                        Related Topics

                                        Collapse

                                        • Tynan Dill
                                          Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?
                                          by Tynan Dill
                                          I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.

                                          Upon bringing it home and plugging it up, it showed a standby light.

                                          I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.

                                          The screen seems to blackout and stay black, but with a flashlight I can see the display.

                                          With my Playstation 4 connected via HDMI, and running a game I can hear sound.

                                          Assuming...
                                          11-22-2024, 01:46 PM
                                        • m1ch43lzm
                                          HP Pavilion 15-eh Board DAG7HAMB8F0 - CPU throttling to 0.4GHz (PROCHOT_EXT) and black screen
                                          by m1ch43lzm
                                          Hi, this is my personal laptop, which the original board (lets call it Board A) blew up PU8700 (TPS51486), making a hole on the board, i had left the laptop at my desk one day with the battery fully charged and didn't touch it for a week, but when i tried to turn it on it didn't
                                          Thought the battery was dead, so i plugged in the charger then tried to power on, the power LED blinked once, charged LED still orange, unplugged the charger, plugged in again and I noticed the "magic smoke" smell, so i unplugged the charger, removed the back cover and saw the blown IC (the "magic...
                                          05-12-2025, 08:37 PM
                                        • Hakuu
                                          LG OLED77G1PUA - No Video / Audio after a TCON Board change and Software Update
                                          by Hakuu
                                          Hi There,

                                          This TV was auto switching off after few seconds with some vertical lines on the screen, so got a new TCON board and replaced it.

                                          After replacing the TCON board it was working fine and i set it up with everything, used for few hours, then had the bright idea to update the software on it. During the update process, TV switched off and now no audio or video. No relay switch sound.

                                          More Details

                                          TV Model - LG OLED77G1PUA

                                          Got the same exact TCON board from TVPartsToday and replaced it. But didnt transfer the EPPROM data (didnt...
                                          07-12-2023, 02:37 PM
                                        • canadaboy25
                                          Panasonic TC-P54VT25 No image. A or D board?
                                          by canadaboy25
                                          I have a Panasonic TC-P54VT25 that will power on and prime the display but there is no image at all.

                                          The panel is primed as there is a slight glow from the entire panel. This means the problem should be logic related. The service manual also confirms this and recommends replacing the A or the D board.

                                          I have tried to get the TV to display the test sequence but I have been unable to and I don't even know if this TV has a test sequence or not. I tried following tom66's instructions in post #3 on this thread https://www.badcaps.net/forum/showthread.php?t=26790. There was...
                                          01-17-2021, 01:06 AM
                                        • sam_sam_sam
                                          Panasonic switching power supply daughter board has two 27uf @ 50 volt capacitors which I do not keep in stock
                                          by sam_sam_sam
                                          I did not have any 27uf @ 50 volt capacitors but one nice thing is that it has enough room for two capacitors in parallel a 22uf and a 4.7uf @ 50 volts 22 plus 4.7 equals 26.7uf which so very close to 27uf I will show some pictures of it sometime tomorrow

                                          This is one of the shit est boards I seen in a very long time and it was the daughter board the traces just lifting off the board I had to use the capacitor leads to repair the the traces and the main board is not any better because I had to repair several traces for the daughter board to the main board

                                          After all of...
                                          07-13-2024, 08:14 PM
                                        • Loading...
                                        • No more items.
                                        Working...