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Emachines!! EMACHINES!! EMACHINES!!!

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    Emachines!! EMACHINES!! EMACHINES!!!

    OK, we have 3 bestec killed emachines. T2862, T3828 and a W2646. The T2862 and the T3828 show a green LED light after the PSU is replaced. The T3828 Shows nothing. On the 2862 I've replaced the mosfets by the CPU and still no change. No caps are visibly broken but then again we have no ESR meter yet. Any ideas on what else fails on these boards that would prevent them from even running the fans but still show a green LED on the board. This seems like a very common problem. Thanks!

    #2
    Re: Emachines!! EMACHINES!! EMACHINES!!!

    I have never been able to save an eMachine board that has been BESTEC'ed. KC8 or another pro tech might have more advice for you. I just toss them out.
    This is a real shame, as most of those boards are nice Intel products.

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      #3
      Re: Emachines!! EMACHINES!! EMACHINES!!!

      Generally its the chipset that get fried when the PSU goes over volt crazy.
      Not easy to repair, and certainly not worth the expense.

      Comment


        #4
        Re: Emachines!! EMACHINES!! EMACHINES!!!

        I agree.
        The usual dead part on a "bestec'ed" motherboard is the main chipset.
        If they don't fire up with a good PSU then you are better off replacing them.
        Mann-Made Global Warming.
        - We should be more concerned about the Intellectual Climate.

        -
        Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.

        - Dr Seuss
        -
        You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
        -

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          #5
          Re: Emachines!! EMACHINES!! EMACHINES!!!

          Failed chipsets will still usually allow the fan to spin up and the pc to power up. Chipsets do not get hot, don't look burnt.
          1/2 the cpu mosfets short to ground off one leg, even after replacement. Something else is shorted or not functioning, power chip, a mosfet, diode, etc. Anybody replace either bga chip and have it come back?

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            #6
            Re: Emachines!! EMACHINES!! EMACHINES!!!

            >> Chipsets do not get hot << - Then they probably aren't working.

            There are something like 5? 10? local voltage regulators that supply the chipset with different voltages via POL [Point of Load] regulators. If you fried the VRM MOSFETs with excessive voltage the smaller regulators are probably damaged too.

            If time is not a consideration you may be able to fix it but there is no guarantee and the odds aren't in your favor.

            .
            Mann-Made Global Warming.
            - We should be more concerned about the Intellectual Climate.

            -
            Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.

            - Dr Seuss
            -
            You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
            -

            Comment


              #7
              Re: Emachines!! EMACHINES!! EMACHINES!!!

              time is not an issue, boards are being replaced. still want to make them work. gonna fix the power supplies too but getting new ones for these. with so many of these failing there has to be someone who found the parts that died they are prob the same on all of them.

              Comment


                #8
                Re: Emachines!! EMACHINES!! EMACHINES!!!

                Originally posted by NxB
                time is not an issue, boards are being replaced. still want to make them work. gonna fix the power supplies too but getting new ones for these. with so many of these failing there has to be someone who found the parts that died they are prob the same on all of them.
                southbridge.

                Comment


                  #9
                  Re: Emachines!! EMACHINES!! EMACHINES!!!

                  Hi folks.
                  Currently running on an Emachines 530 Pentium 4 machine. No faults - yet, so may have a peek next time I'm in there. Cooling sounds a bit noisy at the mo, so that will be before the summer.
                  Really joined the forum because of a sony handycam - that may have a notorious bad cap problem. Really came to learn from those who know about SMD's. Surprised that these can go bad as I thought SMD's were very robust. Now I find there are fake components out there

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                    #10
                    Re: Emachines!! EMACHINES!! EMACHINES!!!

                    Ah.. the old Sony fishcaps* That takes me back.....








                    ...to the days of shear hell changing dozens of SMD capacitors, stinking the workshop out in the process.. burning your fingers as you try and push the cap over to one side so you can get the other lead unsoldered.. getting pissed off as you'd replaced one in the wrong order and now have to remove it again so you can solder the one near it.. finding out the replacements are 5% bigger and wont fit..



                    I glad those days have gone.



                    * so called because they smell of rotting fish when you heat with soldering iron.

                    Comment


                      #11
                      Re: Emachines!! EMACHINES!! EMACHINES!!!

                      I have repaired four Bestec power supplies in the past few months. Two were Model ATX 250-12E, and both had problems (including visible burn damage) in the 5VSB circuitry. One required replacing three bulging caps and it was fixed. One was a b@#$%^&* and required maximum effort! I completely modified the circuit with a add on board. The other two were Model ATX 250-12Z. One had a shorted main switching transistor (which also took out the pwm chip). The other had a bad resistor which caused the supervisory chip to shut down the power. Both of these (Model ATX 250-12Z) have a pwm chip (A6351A) in the 5VSB circuit, and both had no trouble with the 5VSB.

                      Bestec PSUs can be repaired, but it does require determination. The PSUs with the bad 5VSB are probably the mobo killers. Have fun.

                      Tom
                      Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)

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