How do I identify the primary and secondary windings on a transformer?

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • budm
    Badcaps Legend
    • Feb 2010
    • 40746
    • USA

    #21
    Re: How do I identify the primary and secondary windings on a transformer?

    Yes, on ANY winding (primary or secondary). I doubt very much that you have bad transformer.
    What is the brand and model number of this TV? You can check www.elektrotanya.com to see if it has service manual for your TV.
    OK, then we just need to do step by step testing by check the incoming AC and see if it reaches the Bridge rectifier (I will assume you have already check the simple stuff like fuses already). Then see if you do have 165V on the large DC filter cap in the Hot side (primary side of the circuit). I will wait for the pictures of the board to give you more details, just make sure the pictures are clear and well focused, and use the GO ADVANCED to attach the pictures for posting.
    Last edited by budm; 10-17-2012, 10:40 PM.
    Never stop learning
    Basic LCD TV and Monitor troubleshooting guides.
    http://www.badcaps.net/forum/showthr...956#post305956

    Voltage Regulator (LDO) testing:
    http://www.badcaps.net/forum/showthr...999#post300999

    Inverter testing using old CFL:
    http://www.badcaps.net/forum/showthr...er+testing+cfl

    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
    http://s807.photobucket.com/user/budm/library/

    TV Factory reset codes listing:
    http://www.badcaps.net/forum/showthread.php?t=24809

    Comment

    • mattpd
      Badcaps Veteran
      • Oct 2012
      • 301
      • USA

      #22
      Re: How do I identify the primary and secondary windings on a transformer?

      I also doubt the transformer is bad, just trying to figure out how to use this ring tester. Thank you for willing to help with this project, but should I start another thread first?

      TV is a Panasonic TH42PD50U and the P-Board number is TNPA3570, I have the service manual but I am still new, so maybe you can help me understand it better. I don't have the board in front of me right now, so no pictures yet. I just now got the TV back in my possession so I will be able to hook to board up and test voltages later. I have already tested fuses, and I also checked the ESR/cap of the filter and tested the bridge rectifier and the secondary diodes. They all tested OK but I have yet to put power on them. I will do that later today.

      EDIT: I just tested the voltage at the bridge rectifier and it is getting 0 AC volts... I guess that narrows things down a good bit. What would fail between the fuses and the bridge rectifier?

      EDIT AGAIN: I just tested the known good board AC voltage at the rectifier and it shows 0 also. Now I am confused... Does the board need to be switched ON to see the voltage? I have it outside the tv now.

      Sorry, all I have is my camera on my phone. If you need more close up, let me know.



      Last edited by mattpd; 10-18-2012, 09:44 AM.

      Comment

      Related Topics

      Collapse

      • Spoonicks
        Samsung 2233SN no CFL backlight
        by Spoonicks
        Hello,

        Have a Samsung 2233SN with no CFL backlight. Testing with a flashlight, I can see the image is displayed, but the backlight fails after some seconds.
        Sometimes, after being off for a while, the backlight will remain on for a couple minutes, but most of the times it fails immediately.




        I tried to follow the guide present in this forum, but so far I haven't de-soldered any components. I need some advice on how to proceed to diagnose this display.

        Following the guide I tested the following:

        The transformer...
        07-01-2023, 11:10 AM
      • bauto601
        KDM 480W PSU upgrade succes! (opinions?)
        by bauto601
        Back in 2020 i bought a (2nd hand) compact ATX psu to replace my current one. My PC case only fits very short ATX power supplies so i didn't really have the choice of buying a decent 80Plus unit. The current unit is a modded YoungYear unit that i made a thread about a while ago:
        A "nice" YoungYear unit? - Badcaps

        The "new" unit is a KDM-M6480 480W psu, the 480W number is a typical KDM bullshit claim of course, but the 24A rating on the 12V rail seemed reasonable and the "Active PFC" claim gave me a bit of hope that this was going to be decent-ish....
        12-26-2023, 03:05 PM
      • momaka
        KingWin ABT-650MM 650 Watt ATX PSU [PCB: SW8835REV:A]
        by momaka
        For today's thread, I have a KingWin ABT-650MM ATX PSU. Official web page with the PSU specs is still up and can be found here:
        http://www.rmac.kingwin.com/products.../abt_650MM.asp

        I just can't help it when I see a broken / for parts PSU on eBay that's listed for cheap and looks at least somewhat interesting. Well, OK, I won't lie – on the outside, this PSU looks anything but interesting. It's a plain gray box with colorful β€œspaghetti cables”.




        What mostly drew me into buying it is its 2x PCI-E power connectors...
        03-29-2022, 11:34 PM
      • angelos
        Technics Transformer question.
        by angelos
        Hi there,
        I have this CD player from a Technics Component unit whose mains transformer is blown. The primary winding is open circuit. This transformer has many secondary windings on its secondary side. This transformer is obviously obsolete.
        I need to know if my trick for a alternative transformer will work. Please check the attachment for explanation.
        I want to use three separate transformers to be equivalent like the original transformer.
        The only thing a bit dodgy is the connection of the 9.6V and 12V outputs of which there is a interconnection between the two windings....
        09-14-2022, 02:14 AM
      • OrganiK
        Broken transformer on Carlsbro GRX7
        by OrganiK
        Hi all, to summarize I cant work out what the windings ratio, or rather what the VAC output of the transformer is.

        A cliente came in with this GRX7 that is a mixer/power amp, quite old thing. Said it stooped working so he opened it up, saw a loose wire and connected it to where he though it went, but of course that didn't fix.

        So i open it up and found the transformer was not connected up.

        The transformer has 2 primary windings, and 1 secondary winding I live in Spain and we have 240VCA so naturally the to primary coils where connected together, but there...
        05-15-2019, 11:22 AM
      • Loading...
      • No more items.
      Working...