NM-D521 rev. 2.0 output voltage on CPU coils seemingly low

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • David Miteff
    New Member
    • Dec 2024
    • 1
    • Bulgaria
    #1

    NM-D521 rev. 2.0 output voltage on CPU coils seemingly low

    Hello, guys!
    As the title says - the board is NM-D521, on the input of the CPU coils I read 1.2-1.3V, which should be normal, but on the output I read around 0.6-0.8V. The laptop bootloops with no picture.
    As of right now I don't have a thermal camera, so I can't confirm a shorted or partially shorted CPU chip. Do you have any other suggestions as of why the output voltage might drop like that?
    Tags: None
    • mon2
      Badcaps Legend
      • Dec 2019
      • 13868
      • Canada
      #2
      CPU may be in speed throttling mode due to a missing thermal sensor.

      Remove all power. Measure the resistance to ground of the CPU vcore voltage.

      Test the resistance from PU5400, ACN to the same CPU vcore voltage rail to confirm if the high side mosfet(s) are leaking or not.

      What is the voltage to ground of PU5400, ACP and ACN? Is each stable?

        Comment

        Previous template Next

        Related Topics

        Collapse
        • electron_jj
          Panasonic TH-L42D25A checking the PSU output voltage
          by electron_jj
          Hi Everyone, I am new to this forum. I have a Panasonic LED TV which doesnt turn on and is blinking 4 times repeatedly when I turn on the switch. The TV does not respond to the remote control so I had to turn on using the physical switch on the side of the TV. When I turn on the switch the 4 x blinking starts and repeat itself until I turn off the TV. There is a black screen. I turned off the light in the room to check the panel and I think there is no backlight as far as I can tell.

          I have been inspecting and testing the capacitors and diodes in the power supply board to try to...
          08-29-2021, 08:13 AM
        • Document Archive
          MT3608 Step-Up Converter IC Datasheet
          by Document Archive
          The MT3608 is a constant frequency, 6-pin SOT23 current mode step-up converter intended for small, low power applications. The MT3608 switches at 1.2MHz and allows the use of tiny, low cost capacitors and inductors 2mm or less in height.

          Internal soft-start results in small inrush current and extends battery life.

          The MT3608 features automatic shifting to pulse frequency modulation mode at light loads. The MT3608 includes under-voltage lockout, current limiting, and thermal overload protection to prevent damage in the event of an output overload. The MT3608 is available...
          10-07-2024, 05:02 AM
        • Ri5ux
          Playstation 5 2 Second BLOD, F3501 Voltage Output Question
          by Ri5ux
          Hi there, just wondering if anyone out there who has a semi-working or working PS5 board could check the output voltage on F3501's buck converter for me, with and without power. I have 12V on the input, fuse not blown, no output voltage on that IC, with or without power, and no shorts present.

          Symptom: 2 Second BLOD
          Testing: All other rails seem present. APU, SSD, South Bridge, and RAM confirmed to be powering up using a thermal camera. Monitoring the current draw of the 12v rail shows a somewhat normal boot cycle of the south bridge. Jumps up to 300ma, and down to 0....
          09-09-2023, 06:57 PM
        • labello
          Power supply Termaltake Smart Se 630w any voltage in output
          by labello
          Hello everybody I try to fix thi power supply, I have voltage in bridge rectifier, and also in the large capacitor , so I thought the problem was in the pfc but then I found all mosfet ok(tested out of the circuit so I just moved on in the low voltage and here I found a short of one of the diode rectifier. I'll replaced it already but it's completely dead, I mean any stanby voltage and the other voltage is not present. I don't have oscilloscope to understand if the chip work how can I test it? Thank you for the help 🙏
          09-09-2023, 12:06 PM
        • dicky96
          L4973V5.1 Power supply giving too much output voltage
          by dicky96
          Hi guys
          This power supply is from an FM Radio transmitter

          It takes an input of 28V and should output some lower voltage. When I first looked at it I found that there is a zener diode D3 directly across the V out to ground and it was short circuit.

          I removed the Zener, there are no markings to determine it's correct value, and I don't know what Wattage it should be either, plus it broke in half. I took a photo comparing it to a 1N914 signal diode and a smaller zener which I have (which I think are 0.5W but I am not sure) and also a resistor so maybe someone can...
          01-15-2021, 06:29 AM
        • Loading...
        • No more items.
        Working...