Help Understanding Discharging Circuit on Laptop Motherboard

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • Zentech
    Senior Member
    • Feb 2021
    • 94
    • Usa
    #1

    Help Understanding Discharging Circuit on Laptop Motherboard

    Ok, I have an HP Pavilion G6 and I'm trying to understand the "Discharging" circuit on the motherboard DA0R53MB6E1 REV E R53. I'm going to link to the diagram here https://cdn.badcaps-static.com/pdfs/...3fee8687da.pdf
    Discharger circuit is on page 41. So PU12 is the driver for all the MOSFET, my question is when you plugin the charger and before you press the power button, are you expected to have power on the source of MOSFET? Let's take for example PQ55, which is suppose to have 3V on Source. But with power off, there's no 3VS5 on Drain, so no 3V on Source. Is this the expected behavior.
    The reason I'm interested in knowing this is because this 3V on pin 123 of PQ55 are connected to the KBC pin 11 VCC. So I'm trying to figure out if these need to be present for the KBC to work, since in my situation is not working. Motherboard is not coming on. Even when I press the power button. I have all my other voltages on KBC except VCC pin 11. (KBC is on page 33)
    Thanks
    schematic will be attached
    Attached Files
    Tags: None
    Previous template Next

    Related Topics

    Collapse
    • Geeker007
      9th Gen Dell Optiplex Micro PC motherboard repair: Short Circuit?
      by Geeker007
      Hi All, I have a 9th Gen Dell Optiplex micro PC motherboard which doesn't power on. When I connect the motherboard with power adapter, it goes into safe mode and turns off. So from info I have gathered online, it looks like there is a short circuit on the motherboard. So can you guys help me with figuring out the issue?

      I am new to electronics repair, so my queries could be naive but I am ready to learn.

      So I have a multimeter and a solder with me. But I can try to get a variable voltage power supply with a thermal camera as well. From what I seen online, best way is...
      01-28-2025, 03:31 PM
    • glovecaps
      Asus ROG Strix Scar G533qm with a G733qm Motherboard, can I modify the Bios to accept G533 Bios
      by glovecaps
      Hello,

      I have a Asus ROG Strix Scar 15 (G533QM) that had a dead motherboard (Graphics card dead) and after trying to fix the motherboard with no success, I bit the bullet on a sale for a new motherboard. I ordered a motherboard for the 15 inch model which is the one that I have, and when the motherboard arrived it wasn't for a little while that I saw it was from the 17 inch model.

      My question is, can I update the Bios on this G733 motherboard to a G533 Bios.

      The reason for wanting to do this is that the keyboard isn't working as it should, and I think this...
      11-25-2024, 04:23 PM
    • Archimedes
      HP Envy 17-3290NR 3D Blank Screen - motherboard Louis V1.1 6050A2489901
      by Archimedes
      Subject is a blank screen issue in HP Envy 17-3290NR 3D version laptop with motherboard Louis V1.1 6050A2489901 MB-A02. Production year is 2012. This one is a 2nd hand motherboard which I could use it for few months only. Suddenly no output from the internal display and also no signal from HDMI port then Windows out of order after few boots.

      Caps lock working normally and no HP's caps-lock warning blinks. Making a hard reset and replacing the RAM sticks or using different slots didn't help.

      Fans are spinning. Blindly could install windows11 and got the device manager...
      07-30-2024, 05:14 PM
    • momaka
      ASUS P5GC-MX motherboard recap
      by momaka
      Here’s another motherboard that needed a full recap: an ASUS P5GC-MX.
      This one was gifted to me some years ago by user Pentium 4, along with a few other goodies. It actually came in working order with no bulging or leaking caps. However, I noted there were United Chemicon KZG caps everywhere on the motherboard. The CPU VRM output (CPU V_core) was the only exception: it had only 2x KZG. The rest was 6x UCC TMV 4V 680 uF caps… which aren’t any good news either.

      So here is what the motherboard looked like with its original caps:


      CPU VRM area up close…...
      01-27-2021, 11:59 PM
    • dragon3x
      After updating motherboard capacitors, what to do next (Asrock K7VT2, SOLTEK SL-75FRN2L)
      by dragon3x
      Hi, I have some 32 bits computer motherboards that need repair, as they fail to
      power on.

      Here are some examples :

      (N.B. "capacitors" indicated here are electrolytic capacitors located in the onboard
      switching supply area).
      (N.B. #2 : I could not find a 3300 microF aluminum-polymer with a higher voltage
      than 6.3 V.)

      1 - Motherboard #1 : this is an Asrock K7VT2 (socket A) that still works well. To put it on test
      I replaced capacitors with aluminum-polymer.
      3300 microF/6.3 V. x 4 replaced by 3300 microF/6.3 V. (KYOCERA...
      03-21-2025, 02:46 PM
    • Loading...
    • No more items.
    Working...