Dead & noisy Liteon charger

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • teeb
    Member
    • Feb 2012
    • 21

    #1

    Dead & noisy Liteon charger

    hi fellas,

    I've recently been given a supposedly faulty laptop by a friend. In fact it was the PSU that was malfunctioning.
    It's the first time I crack open one of those "power brick" and I was amazed by how "packed" everything was. Furthermore, the added isolant/glue whitish thing really doesn't help figuring out the PCB's layout.

    LITEON 19V - 4.74A
    MODEL: PA-1900-03

    It makes a weird beeping sound when connected to AC.
    - Main cap reads 320V,
    - the 3 tiny ones near the main cap read 10V
    - the 2 green caps on the right, i got 0 on my DMM, I think that the current isn't even going up to there (they seem to charge with current when I set my DMM to diode tester and then quickly set it to 20 DC to read voltage)
    - the fuse near the power plug is ok (0.5Ω)
    - secondary (or is it "primary"?) winding keeps changing value from 0 to 0.3V

    Here is a youtube video of the said noise: http://www.youtube.com/watch?v=CMyPDSPI20k

    Could you please tell me what I should do next?
    Attached Files
  • tom66
    EVs Rule
    • Apr 2011
    • 32560
    • UK

    #2
    Re: Dead & noisy Liteon charger

    I have the innards of a very similar HP laptop charger. I would check for shorted diodes on the secondary and replace the startup cap. These things bake their caps alive so it might not be a bad idea to replace the Taicons too.
    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

    • ratdude747
      Black Sheep
      • Nov 2008
      • 17136
      • USA

      #3
      Re: Dead & noisy Liteon charger

      The taicons gotta go... No two ways about that.

      Once that is done, see if the noise is still there... if so, then it is more than a simple cap issue.
      sigpic

      (Insert witty quote here)

      Comment

      • ratdude747
        Black Sheep
        • Nov 2008
        • 17136
        • USA

        #4
        Re: Dead & noisy Liteon charger

        The taicons gotta go... No two ways about that.

        Once that is done, see if the noise is still there... if so, then it is more than a simple cap issue.
        sigpic

        (Insert witty quote here)

        Comment

        Related Topics

        Collapse

        • BTubbs200
          Dead Dell Latitude 5420 not receiving 20 volts from USB-C charger
          by BTubbs200
          Hello,

          Dell Latitude 5420 P137G
          Board: LA-K491P REV A01

          I have received this laptop which was described as "does not power on or accept charge." Battery shows no sign of charging when charger is plugged in, nor does the board show any signs of life when battery is unplugged and charger is plugged in. No light from the LED at all or any other indications of activity.

          Board seems to have no shorts, all power rails are fine and show high resistance.

          When charger is plugged in, voltage is present in 3.3V rail but absent in others....
          01-24-2025, 08:15 PM
        • Document Archive
          ISL88739AHRZ ISL88739 Laptop Battery Charger Datasheet
          by Document Archive
          The ISL88739 & ISL88739AHRZ are a highly versatile combo battery charger
          configurable for operating as either a Hybrid Power Boost (HPB)
          charger or a Narrow VDC (NVDC) charger, supporting 2-, 3-, or
          4-cell batteries. Both configurations allow the battery to work with
          the adapter together to supply the system load when it exceeds
          the adapter capability, referred to as system Turbo mode. HPB
          charger configuration reverse-boosts battery energy to the system
          bus to help the adapter provide the system power in Turbo mode.
          NVDC charger configuration...
          11-05-2024, 03:28 PM
        • flat-earther
          how to prevent a connected charger from draining battery when not charging?
          by flat-earther
          I have an RC radio handset(Taranis QX7) which doesn't have internal battery charger which means I had to remove the battery every time I needed to charge it.
          So to improve it, I added a 15W USB-C charger board(link) inside and soldered it to the same connector on the PCB where the battery plugs into, great, now I can simply charge it with a USB-C cable.

          but the problem I found is that after the radio sat for two weeks without being used the 2S 18650 battery that I'm using was at 4.2V!
          So the battery is backfeeding the charger and being drained.

          How can I prevent...
          08-07-2025, 01:04 PM
        • s_henya
          Liteon PA-12617 dead (Lenovo ideacentre3)
          by s_henya
          Hi Guys,
          Trying to save this PSU from going to the bin.
          PSU was found dead:
          1.. Main fuse blown
          2. Main switching transistor shortes
          3. rectifier bridge shorted
          4. low ohm resistor blown

          replaced all of the above (resistor was replaced with a. Thin wire since i don't know what was the original value)

          Have 330v on main cap. But standby is still not right.

          maybe the driver chip died?...
          09-06-2024, 03:15 AM
        • flat-earther
          ASUS X54H laptop thinks it's always charging even with charger unplugged
          by flat-earther
          The charging indicator light on my ASUS X54H laptop is always on even when the charger is disconnected.

          Windows also shows ''Plugged in'' when charger is not connected.

          This problem started year ago gradually, when unplugging the charger the charging light took several seconds to disappear, then minutes, and now almost always on even when unplugged for an entire day.
          Strangely, before sometimes immediately when plugging in the charger the charging light went away, and later came back with it connected.
          If I let battery run out and say it has 3% Windows will...
          06-24-2025, 09:32 AM
        • Loading...
        • No more items.
        Working...