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Mosfet interchangeability-A4710 with 4712

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    #1

    Mosfet interchangeability-A4710 with 4712

    Hi, I have an ACER 5820TG that only boots as far as the Acer logo and then shuts down. It won't boot again unless the AC plug is removed and re-inserted. I have found a mosfet that is faulty. It is AO4710. My question is can I use a Vishnay 4712 as a replacement? The data sheets are here http://www.vishay.com/docs/65170/si4712dy.pdf and here http://aosmd.com/pdfs/datasheet/AO4710.pdf. So that I don't have to ask in the future, can somebody tell me what the crucial parameters are? I know it has to be the same channel, voltage and dimensions but is there anything else I should look for on the data sheets? Grateful for help, as always.
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    #2
    Re: Mosfet interchangeability-A4710 with 4712

    Sorry, the link to the 4712 is here

    http://www.vishay.com/docs/65170/si4712dy.pdf

    Maybe I'll just do it!

    Comment

      #3
      Re: Mosfet interchangeability-A4710 with 4712

      I had to deal with just such a repair job...
      Originally posted by tom66 View Post
      You don't usually need to be worried about VgsTH as it's so variable (there, alone, it has a 250% tolerance -- most basic semiconductor properties are not well controlled.) Instead, compare RdsON vs Vgs; if the current device has x.x ohm at x.xV Vgs, you need to meet or go lower than that.
      So the voltage can be higher, it's just a maximum rating, but the most important thing is that the RdsON matches or exceeds the spec. So it should be lower at equivalent draw.

      The AO4710 has a typical RdsON of 11.7 mOhms @ 4.5V 11A, while the Vishay si4712dy has a rating of 13 mohms @ 4.5V 10A. So the Vishay part is actually slightly inferior. If you tell me which site your ordering from, I might be able to find you something better.
      "We have offered them (the Arabs) a sensible way for so many years. But no, they wanted to fight. Fine! We gave them technology, the latest, the kind even Vietnam didn't have. They had double superiority in tanks and aircraft, triple in artillery, and in air defense and anti-tank weapons they had absolute supremacy. And what? Once again they were beaten. Once again they scrammed [sic]. Once again they screamed for us to come save them. Sadat woke me up in the middle of the night twice over the phone, 'Save me!' He demanded to send Soviet troops, and immediately! No! We are not going to fight for them."

      -Leonid Brezhnev (On the Yom Kippur War)

      Comment

        #4
        Re: Mosfet interchangeability-A4710 with 4712

        Thank you for that. I was starting to think nobody liked me, lol. impossible. I was actually going cheap and salvaging off a scrap motherboard. Now that I know a little more of what to look for I'll see what else is on my supply of dead MB's but I guess digikey would be one to buy from if tey sell in low qty. Mockingbird is this a similar repair to the one you did - an ACER 5820TG?
        Last edited by sparker1; 04-30-2013, 10:09 PM.

        Comment

          #5
          Re: Mosfet interchangeability-A4710 with 4712

          No, I am repairing an old LCDTV. It uses the same package type (soic-8 or SOP-8), but it's unique in the sense that it has both an N-Channel and P-Channel MOSFET in one.

          No need to buy anything really, I think the 4712 will be just fine.

          I had to use two irons to remove the thing.
          "We have offered them (the Arabs) a sensible way for so many years. But no, they wanted to fight. Fine! We gave them technology, the latest, the kind even Vietnam didn't have. They had double superiority in tanks and aircraft, triple in artillery, and in air defense and anti-tank weapons they had absolute supremacy. And what? Once again they were beaten. Once again they scrammed [sic]. Once again they screamed for us to come save them. Sadat woke me up in the middle of the night twice over the phone, 'Save me!' He demanded to send Soviet troops, and immediately! No! We are not going to fight for them."

          -Leonid Brezhnev (On the Yom Kippur War)

          Comment

            #6
            Re: Mosfet interchangeability-A4710 with 4712

            Couldn't find one on the scrap boards. This one (AO 4410) looks like it would do http://www.ebay.com.au/itm/5PCs-ORIG...item589a6a8283. The specs are here http://aosmd.com/pdfs/datasheet/AO4410.pdf. It doesn't have a schottky diode only a plain one. Do you think there would be any problems?
            Last edited by sparker1; 04-30-2013, 11:55 PM.

            Comment

              #7
              Re: Mosfet interchangeability-A4710 with 4712

              Originally posted by mockingbird View Post
              No, I am repairing an old LCDTV. It uses the same package type (soic-8 or SOP-8), but it's unique in the sense that it has both an N-Channel and P-Channel MOSFET in one.

              No need to buy anything really, I think the 4712 will be just fine.

              I had to use two irons to remove the thing.
              I didn't read your second post until now. I'll use the 4712 Thank you again for your input.

              Comment

                #8
                Re: Mosfet interchangeability-A4710 with 4712

                Absolutely destroyed the mosfet trying to get it off the old board. I need to learn how to do this.

                Comment

                  #9
                  Re: Mosfet interchangeability-A4710 with 4712

                  Just make sure not to rip off pads when you're removing it from the board you're repairing.

                  Add a blob of solder to both sides of legs (Being careful not to get it on nearby tiny SMD caps or resistors), heat the blobbed pins with soldering irons from both sides at the same time, lift off. Make sure not to drop it on the motherboard because if it falls on something while it has some molten solder attached to it, the solder could stick to something important on the board.

                  After, clean pads with wick, clean off flux residue making sure not to damage pads, and put in new SOP8/SOIC-8 package using the corner pin tack method.
                  "We have offered them (the Arabs) a sensible way for so many years. But no, they wanted to fight. Fine! We gave them technology, the latest, the kind even Vietnam didn't have. They had double superiority in tanks and aircraft, triple in artillery, and in air defense and anti-tank weapons they had absolute supremacy. And what? Once again they were beaten. Once again they scrammed [sic]. Once again they screamed for us to come save them. Sadat woke me up in the middle of the night twice over the phone, 'Save me!' He demanded to send Soviet troops, and immediately! No! We are not going to fight for them."

                  -Leonid Brezhnev (On the Yom Kippur War)

                  Comment

                    #10
                    Re: Mosfet interchangeability-A4710 with 4712

                    Originally posted by mockingbird View Post
                    Just make sure not to rip off pads when you're removing it from the board you're repairing.

                    Add a blob of solder to both sides of legs (Being careful not to get it on nearby tiny SMD caps or resistors), heat the blobbed pins with soldering irons from both sides at the same time, lift off. Make sure not to drop it on the motherboard because if it falls on something while it has some molten solder attached to it, the solder could stick to something important on the board.

                    After, clean pads with wick, clean off flux residue making sure not to damage pads, and put in new SOP8/SOIC-8 package using the corner pin tack method.
                    Thank you once again. I'll use your advice for some much needed practice. I've seen a few youtube videos on how to remove SMD components and they make it look so easy. My efforts so far have involved carbonating the component, burning the pads and/or my fingers and a lot of cursing. The only ones I've had success with are removing smd caps.

                    Comment

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