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Main problem with toshiba l735

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    Main problem with toshiba l735

    I there guys , i hope all is good with all of you ,

    Well today i received a toshiba l735 with 19 volts rail in short , First power diode was in short , changed it and no more short on the dc supply , but the main step controller was also getting very hot , In this case it was a uP6188A, since i didn't have any of does in stock , after a bit of search i've found that the ISL6237 could be used instead , changed the main step controller , now i've got 19 volts everywhere , but there was still no 3.3 and 5 volts , and also noticed that ISL95835(cpu core) is getting warm , found the problem on the 5 volts line , was both mosfet were dead , replaced them , voila , got 3.3 and 5 volts line good , pilot light turn on , and also machine turn on but turn off after a while , cpu don't get hot , always cold , assuming that the ISL95835 is getting a bit hot , guess is not ok , making the signal from KB controller that communicate with the cpu core to give a order to shutdown the machine since cpu core ic is not ok , also noticed that even with pilot led on , bios is with 0.25 volts , and its goes to normal value(3.33V)when i turn the machine on , im really almost sure that KB controller doesn't enable well the signal since cpu core ic is not ok .
    My main question is , since i don't have in stock , ISL95835 , with which IC i can replace this one ? i know this ISL is Compliant with IMVP-7/VR12TM , i cheked a few and found some related items , does that i will write down .

    ISL6353 Multiphase PWM Regulator for VR12 DDR Memory Systems
    ISL6363 Multiphase PWM Regulator for VR12TM Desktop CPUs
    ISL6364 Dual 4-Phase + 1-Phase PWM Controller for VR12/IMVP7 Applications
    ISL6364C Dual 4-Phase + 1-Phase PWM Controller for VR12 Desktop Applications
    ISL6366 Dual 6-Phase + 1-Phase PWM Controller for VR12/IMVP7 Applications
    ISL95831 3+1 Voltage Regulator for IMVP-7/VR12 CPUs
    ISL95837 3+1 and 1+1 Voltage Regulator for IMVP-7/VR12TM CPUs

    Well would be nice finding a solution instead of waiting some weeks for a component to arrive .And since i've got around 400 stopped board for spares and none of them have this IC , need to find a good replacement .

    wait for your expert taughts on this.

    highly appreciated your comments and suggestions.

    sincerely

    jonathan
    Last edited by highpulse; 03-06-2014, 03:25 PM.

    #2
    Re: Main problem with toshiba l735

    So from what I can gather, it powers but doesn't POST? If so look for an NEC Tokin cap on the board, some L735 boards did have some square-shaped NEC Tokin caps and suffer the same problem as this https://www.badcaps.net/forum/showthread.php?t=8991
    Dell E7450 | i5-5300U | 16GB DDR3 | 256GB SSD

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      #3
      Re: Main problem with toshiba l735

      hi there and the for you fast reply , well i thinked also on the nec tokin but , the problem is why the ISL CPU Core is getting hot(not burning finger but i notice him hot , even with the machine shutdown (with presence led on ) in any case this token is different from the a200 a300 model , can it be replaced with the tantalum caps as well, in case its also damaged ?

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        #4
        Re: Main problem with toshiba l735

        I'm assuming so, you may want to check the capacitance and polarity of that Tokin cap though. It's been successfully repaired before as per this thread, but no details on the nature of the repair:

        https://www.badcaps.net/forum/showthread.php?t=33961

        Not so sure about the ISL getting hot though. Sounds like a possible short on the CPU rail.
        Dell E7450 | i5-5300U | 16GB DDR3 | 256GB SSD

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          #5
          Re: Main problem with toshiba l735

          yes must vchek better tomorrow , now after 14 hours working , time to rest the anyway for the suggestions .
          Meanwhile if someone know which IC can replace this ISL , i will be very happy

          Comment


            #6
            Re: Main problem with toshiba l735

            i've been trying to get the pinout for this ISL for i can compare with outher , but not finding it , anyone that can help me out giving a link were i could find the pinnout , or a schematic that have this IC

            thk in advance

            Comment


              #7
              Re: Main problem with toshiba l735

              here you go
              page 38
              Attached Files

              Comment


                #8
                Re: Main problem with toshiba l735

                Originally posted by sorinac View Post
                here you go
                page 38

                WEll cheked everything , everything resuming to a ead controler , now i dont have this item in stock , is there any compatible cpu vcore IC that i can use here ??? would be highly apreciated some help in this mather .
                thk in advance

                jonas

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