Help-Component Replacements

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • MEB
    Badcaps Veteran
    • Sep 2013
    • 371
    • USA
    #1

    Help-Component Replacements

    I am attempting to learn all I can from you guys. I currently have low electronic knowledge, but hoping that will improve. I have been fortunate to have budm get me going on the repair of a Dell 2007WFPb on an existing thread. But to give him a break, and thinking this is the correct place to post my current questions here goes.

    budm has identified the components shown on the 1st photo as part of 4
    buck regulator circuits which exist on my USB/DC onverter board. I have been able to find at least one shorted Mosfet J598 which I have found from the forum to be equivalent to SJ598. I can find no datasheet on the
    J598 but have included one from the NEC SJ598. Both I only can find on ebay and am leary. So I am including datasheets from what I think to be similar Mosfets, but I don't know enough to make that decision. Please look at the Fairchield and Infineon Mosfet datasheets included and tell me if they are or are not suitable replacements.

    Also shown on the 1st photo are S4 devices which were identified as 40V, 1A Schottky diodes. budm suggests replacing them with a 40V, 2A device. Again I have included a datasheet for an SS24 which I would like to know if that may be a suitable replacement for the S4.

    If my suggestions are not going to work, I would be extremely grateful to know if anyone knows or has successfully replaced the J598 Mosfet and the
    S4 diode. Thanks.
    Attached Files
    Tags: None
    • LDSisHere
      Badcaps Veteran
      • May 2012
      • 727
      • U.S.A.
      #2
      Re: Help-Component Replacements

      I think the Fairchild to be a better choice than the Infineon FET to replace the J598. The choice of the SS24 as a replacement diode should be a good.

        Comment

        • PeteS in CA
          Badcaps Legend
          • Aug 2005
          • 3581
          • USA, Unsure of Planet
          #3
          Re: Help-Component Replacements

          The full P/N for that MOSFET is 2SJ598, and the way Japan does its semiconductor numbering, other companies cannot make equivalents and use the same part number. I may be incorrect on this, but I think NEC ceased making power MOSFETs, so you're stuck with having to find a close equivalent. The critical parameters are the voltage and current ratings, and the R(DS ON). The gate capacitances are pretty important as well. Higher current rating is OK. Lower R(DS On) and gate capacitances are good. Infineon and Fairchild are good brands; likewise IR, Siliconix and STMicro.
          PeteS in CA

          Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
          ****************************
          To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
          ****************************

            Comment

            • MEB
              Badcaps Veteran
              • Sep 2013
              • 371
              • USA
              #4
              Re: Help-Component Replacements

              Thanks LDSisHere and PeteS. I will obtain replacements per your advice and report back how things went.

                Comment

                Previous template Next

                Related Topics

                Collapse
                • 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
                • Nooy
                  VGA MOSfet permanently shorted and loss of MOSfet pad
                  by Nooy
                  Hello everyone, I recently found this badcaps site and super Learn Electronics Repair youtube channel. And I wanted to learn how to troubleshoot power supplies and VGA cards and how to practice soldering, since I already have a properly defective piece of them. I am currently trying to solve two problems:

                  I have a Gigabyte GV-RX460WF2OC-4GD type card. I managed to find the faulty MOSfet (AON6414A) on it, which I replaced. The card starts up, but after about half a minute, the MOSfet in the same position will be shorted again. Is it possible that the PWM controller driving the MOSfet...
                  02-14-2024, 02:26 AM
                • redbaron1007
                  Help identifying mosfet on Razer Blade RZ09 (CH570_MB_NT)
                  by redbaron1007
                  I have a Razer laptop (RZ09 MB# CH570_MB_NT) that has a shorted mosfet marked BND M03 E067 that I'm unable to find anywhere online. Does anyone either know what the part number is for this mosfet or have a schematic I can find it in?

                  Backstory on the whole thing the laptop was plugged into a lamp at a hotel. The lamp got unplugged while it was charging and now the system won't power on anymore. I found the caps around this mosfet shorted and when I injected voltage into the caps the mosfet got hot and my bench psu was pulling 5A. Pretty sure this is all that's wrong with the laptop...
                  1 Photo
                  09-09-2025, 11:10 AM
                • AppleLover123
                  Asus X712EA 3 volts after the first mosfet
                  by AppleLover123
                  Hey guys,

                  i have a asus motherboard here and as the title says after the first mosfet (in the picture) there is nothing more than 3.15v.
                  I injected 19v and max. 1 amp at the charging port and there is not voltage drop or smth. It's just taking 19v and 1 milliamp.
                  Then i tried to inject 19v and max 1amp after the current sensor and there it first takes 19v and 4 milliamps and after 2 seconds it is taking nothing (no current).
                  I measured on the coils on board everything seems fine. Also the main power rail is not shorted (infinite resistance).
                  Now i thought something...
                  12-15-2024, 07:49 AM
                • MicroSMD Lab
                  ASUS ROG Zephyrus GPU Mosfet repeat failure
                  by MicroSMD Lab
                  The board number is GU502DU. I repaired this a couple weeks ago and it came back with the same issue, same mosfet failed (PQH9201). I'm hoping that the GPU was spared this time.
                  I used the same replacement part (purchased from Mouser) and I'm certain the soldering was done properly since it took just as much effort to remove as before. What could cause this same mosfet to fail? I'm thinking if it was unsuitable then the others would fail too. I looked for similar failures on YTube and the mosfet was replaced with AOE6930 in one instance and AOE6932 in the other but it's possible that the...
                  01-10-2024, 06:36 AM
                • Loading...
                • No more items.
                Working...