mosfet replacement for motherboard

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • stoner
    New Member
    • Feb 2008
    • 1
    #1

    mosfet replacement for motherboard

    Have a question for the experts. I have a gigibyte mothboard GA-7VAX-A Rev 1.0 and am having problems. Removed all the caps and checked, they are fine (since put back on). Have a small brown spot on the back side under the Mosfet (4 of them). They are NEC K3405 (repalcemnts from this forum are the 2SK3405). Wife says just to junk the board and move on, but it and I have fond memories and now it is just a matter of principle(yes I am thick headed). I have an old motherboard that the caps are gone bad on and can rob the Mosfets from that. They are NEC K3296; question: can I use these to replace the NEC K3405(2SK3405) on the gigibyte board that I believe are gone bad (i removed them and checked them with a DMM and they are all differnt readings). Awaiting replies from the experts (i know enough to be dangerous)

    Thanks much
    Stoner
    Tags: None
    • shadow
      Badcaps Veteran
      • Feb 2007
      • 732
      • Australia
      #2
      Re: mosfet replacement for motherboard

      Unfortunately I do not know. However I do know for a fact that others on the forum can give you good advice!

        Comment

        • starfury1
          Badcaps Legend
          • May 2006
          • 1256
          #3
          Re: mosfet replacement for motherboard

          Hi Welcome
          There are a few posts around here dealing with this (search mosfet)

          You would need to check the spec on the Mosfets (off hand, No idea)

          I think from memory you may have to replace the lot or maybe pair
          I don't think (from memory) its a good idea to mix different Mosfets in the VRM circuit.
          (Ditto Caps)
          (you may get away with one of the same type..I think)

          As to worth saving?
          If you got the time skill and use...why not

          As Shadow said there are others much more familiar with this thing here
          (I just know there are posts on your type of question around here)

          Cheers
          Last edited by starfury1; 02-06-2008, 10:37 PM.
          You step into the Road, and if you don't keep your feet, there is no knowing where you may be swept off to." Bilbo Baggins ...

            Comment

            Previous template Next

            Related Topics

            Collapse
            • dhenion
              Asus VivoBook F510UA-AH51 won't run on battery after motherboard replacement
              by dhenion
              I'm working on my sister's laptop: Asus VivoBook F510UA-AH51 - The motherboard died so I replaced it.

              The original board was:
              ASUS X510UNR REV 3.0 A

              The replacement board is:
              ASUS X510UNR REV 3.0 B (identical except B vs A - I couldn't find an A board anywhere. Visually they are identical.)

              It boots right up on the replaced motherboard and everything works fine on the new motherboard - but it won't run off battery. When I disconnect the charger it immediately dies. When I plug it back in and reboot the system - it still shows the battery at...
              1 Photo
              01-30-2024, 01:45 PM
            • DoOm86
              Dual mosfet replacement help
              by DoOm86
              Hello.
              I have a notebook with a shorted mosfet, it's a E6930 GA8125.
              It seems to be a 30V dual asymmetric N-channel AlphaMos.
              Luckily the notebook is working, so I just need to find a good replacement for this mosfet.

              And here is where I need help!
              It's the first time I have to replace this kind of mosfet, I checked on mouse and I found this: (mouser No) = 512-FDPC5030SG.
              I need your help to be sure is a good replacement or there is another with better compatibility, since I can't find the same exact (just from China).
              Thanks!...
              10-31-2023, 12:03 PM
            • jm942
              Hp Lh482p 5 short 3 long short after cpu vcore mosfet replacement
              by jm942
              Hi,
              My laptop went dead and after checking ,the main 19 volt power rail was shorted. After some checks i could identify that a high side vcore mosfet was shorted.
              I replaced the mosfet and now the white powerled is present , fans start spinning but capslock shows the famous 5 long and 3 short code.

              I checked the vcore voltages after replacement and i get for all 1.01 V so means for me that the driver is still working of the replaced shorted mosfet. On the Nvidia i measure around 0.8 V after the mosfets.
              I did voltage injection on the cpu with 0.7V and i have a current...
              07-11-2024, 05:11 AM
            • Jane
              How do you test MOSFET in laptops ?
              by Jane
              I tried to use this method:

              Testing an N-channel MOSFET:

              Step 1: Discharge the Gate (turn off the MOSFET)
              Place the black probe (COM) on the Source (S) and the red probe on the Drain (D). The multimeter should show no continuity (high resistance or "OL" – open line).
              Then, touch the black probe to the Source (S) and the red probe to the Gate (G). This discharges any stored charge in the Gate, turning the MOSFET off.

              Step 2: Charge the Gate (turn on the MOSFET)
              Now, place the red probe on the Gate (G) and the black probe on the              ...
              09-27-2024, 03:31 AM
            • baletak
              Lenovo T490 - motherboard serial - windows licence lost - after corrupt bios chip replacement
              by baletak
              Hi,
              had T490 with faulty bios chip. Bought chip out of ebay and soldered on. Laptop starts and works however serial numbers of laptop and motherboard do not match.
              I have updated laptop model number.

              1) I did not find the way to update laptop serial number - I have this one.
              2) I dont know where to get my motherboard serial number and how to update it. Is it somewhere physically on the mainboard? How do I update it?

              Hope to find someone to help me with this as I am hitting dead end at the moment.

              Many thanks

              Miro
              05-23-2025, 01:21 AM
            • Loading...
            • No more items.
            Working...