Coolermaster RS-460-PCAR-A3

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • rogfanther
    Badcaps Veteran
    • Jul 2006
    • 458
    • Brazil
    #1

    Coolermaster RS-460-PCAR-A3

    Hello,

    among a bunch of other psus ( photos of them later ) , I´ve got this.

    It gives 5VSB ok, but won´t power up. Secondary rectifiers seem to be ok, the least being about 47ohm between their legs. I believe that to be the minimum load resistor in the circuit.

    I´m still tracing the circuit, but it seems the feed to the UC3843B pin 7 is low ( 3.2V, when from the datasheet it should be around 12-14VB. ) . There are two tiny caps near it that I can try changing.

    The pictures I have are bad, will try to get a better camera.

    Thanks for your insight.
    Attached Files
    Tags: None
    • ben7
      Capaholic
      • Jan 2011
      • 4059
      • USA
      #2
      Re: Coolermaster RS-460-PCAR-A3

      Yes, go ahead and replace those little caps, they often fail, and the PSU won't turn on.
      Muh-soggy-knee

        Comment

        Previous template Next

        Related Topics

        Collapse
        • Alimash
          op amp circuit function?
          by Alimash
          Hi,
          I am repairing a ups which doesn't turn on ,it has the following ICs:
          SG3525 used to drive inverter mosfets.
          couple of uc3483, one for the power supply and another to drive a big mosfet at the output stage(i think the technique is called boost)
          A LM358 and TL074 for control mechanism and of course the uController.

          The SG3525 is shutting down every time the ups is turned on.
          I want your help to know the function of LM358 and TL074 in the system.
          I reverse engineered the LM358 circuit and i think that one of the block(A) is used for battery level...
          LM358 circuit
          1 Photo
          07-31-2025, 07:45 AM
        • Astonished
          Fixing the Charge Circuit of the Batteries of the DC Motor
          by Astonished
          Hi friends of electronics

          What you see in the video and pictures attached is the circuit for charging the batteries of a DC motor.

          The problem is that this circuit cannot charge the batteries (3 1800mAH NiMH batteries) any more. When the circuit was OK, its green LEDs lit up one at a time to show that the batteries have charged more. But now that the circuit is flawed, LEDs light up as you see in the video and at the same time successive beeps are heard.

          Please help me fix this circuit.

          (the datasheet of the IC: https://pdf.datasheet.live/28...
          01-28-2025, 06:24 AM
        • rddube
          Lenovo L490 Ram voltage circuit malfunction
          by rddube
          Hello friends,

          Looking for some guidance here. The RAM voltage circuit on this motherboard keeps burning out PU301 which is a RT8231AGQW. Copy of the board with the burnt chip attached with some voltage measurements and copy of the schematics also included.

          I think I've checked almost every component in the circuit, but when I change the RT8231, the laptop starts I have 1.2V on the inductor for about 10 seconds and then the RT8231 goes south and no more voltage on the inductor. All other voltages on the laptop are good, this is the only one conking out for a reason I...
          07-15-2025, 04:41 PM
        • Tarot Superstars
          Short Circuit tester
          by Tarot Superstars
          Hello.
          I have seen a short circuit tester made with 3 * 9V batteries, a voltage limiter component and a resistor connected to the probes of a multimeter.
          The theory is that the meter becomes sensitive enough to read very low resistances and the lowest resistance to ground on a circuit is likely to be a short circuit in that area.

          Link
          The Amazing $1 Short Finder Upgraded! Convert ... - YouTube
          https://www.youtube.com/watch?v=0eixDdCpiO4

          My multimeter isn't normally sensitive to very small resistance, but when I put a 1 mega ohm resistor...
          09-25-2023, 09:11 AM
        • M1NEBLANK SHOW
          MSI B250 Gaming M3 Short circuit in CPU power supply circuit
          by M1NEBLANK SHOW
          Hello. MSI B250 Gaming M3 board, short-circuit on the power supply. Found a problematic mosfet VQ1
          (N-PK616BA_PDFN8-HF) soldered it out - short circuit is gone. I replaced VQ1 + VQ5 (N-PK632BA_PDFN8-HF). VQ1 was replaced with PK618. After starting attempt VQ1 is lit again. What can be the problem? In the driver?

          Schematic and Boardview here
          ...
          04-04-2025, 03:57 PM
        • Loading...
        • No more items.
        Working...