No power to KBC after chip change

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • p1muserfan
    Senior Member
    • Apr 2014
    • 184
    • USA

    #1

    No power to KBC after chip change

    I've got no power TO the KBC chip after replacement, nothing at the 5 power-in pins. Backing up a bit, there is nothing at the resistor before the capacitors leading to the power pins either. Do have 3v at bios chip and 3v from power button at KBC though. Also have 3.3 and 5v from TPS51123
    Attached Files
  • p1muserfan
    Senior Member
    • Apr 2014
    • 184
    • USA

    #2
    Re: No power to KBC after chip change

    Anybody?

    Comment

    • meritosari
      Senior Member
      • Oct 2010
      • 774
      • Indonesia

      #3
      Re: No power to KBC after chip change

      check if there is a short-circuit

      Comment

      • khaahk
        Badcaps Veteran
        • Dec 2013
        • 743
        • Estonia

        #4
        Re: No power to KBC after chip change

        You have to look at Q2703 and Q2705. Why did you change the EC first place? With only battery connected the same thing?
        Check the pictures at this page, was the machine with water damage?
        http://notebook1.ru/forma1/viewtopic...=93849&start=0
        Last edited by khaahk; 11-12-2014, 05:10 PM.

        Comment

        • fddizon
          Badcaps Veteran
          • Sep 2011
          • 555
          • Philippines

          #5
          Re: No power to KBC after chip change

          did you remove cmos battery before removing chip?

          Comment

          • p1muserfan
            Senior Member
            • Apr 2014
            • 184
            • USA

            #6
            Re: No power to KBC after chip change

            Originally posted by fddizon
            did you remove cmos battery before removing chip?
            No Is it trashed?

            Comment

            • Agent24
              I see dead caps
              • Oct 2007
              • 4913
              • New Zealand

              #7
              Re: No power to KBC after chip change

              It might be, I'm not sure. But it's not a good idea to replace things with the power on.
              "Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
              -David VanHorn

              Comment

              • p1muserfan
                Senior Member
                • Apr 2014
                • 184
                • USA

                #8
                Re: No power to KBC after chip change

                Originally posted by khaahk
                You have to look at Q2703 and Q2705. Why did you change the EC first place? With only battery connected the same thing?
                Check the pictures at this page, was the machine with water damage?
                http://notebook1.ru/forma1/viewtopic...=93849&start=0
                I've got 3v at 2 out the 3 legs of Q2703 and 3v at the drain of 2705. I changed the EC because the only way the board would start previously was to remove and then reinsert the cmos battery, mistakenly thought that would fix the problem. Now would kill to go back in time, lol. No water damage either.

                Comment

                • hazardus
                  Senior Member
                  • Apr 2014
                  • 105
                  • USA

                  #9
                  Re: No power to KBC after chip change

                  Remove the cmos battery and short all the pins on EC.

                  Comment

                  • khaahk
                    Badcaps Veteran
                    • Dec 2013
                    • 743
                    • Estonia

                    #10
                    Re: No power to KBC after chip change

                    Double check ec pins for connection or bridges.
                    See if pin 74 on EC is connected to q2705 gate?
                    Try to pull the gate of q2703 to gnd, that should provide 3v to ec.

                    Comment

                    • Ramee
                      Badcaps Veteran
                      • Jul 2014
                      • 218
                      • Israel

                      #11
                      Re: No power to KBC after chip change

                      (khaahk is right) KBC is not sittin well check all pins.

                      Comment

                      • highpulse
                        i hate HP
                        • May 2013
                        • 1489
                        • portugal

                        #12
                        Re: No power to KBC after chip change

                        yes could be not been sitted , chek with a metal pick and pass on all pins , if any move , then resolder again .. i must post a video of how i solder the te KBC's but dont have a good camera and a tripe to do it .

                        Comment

                        • p1muserfan
                          Senior Member
                          • Apr 2014
                          • 184
                          • USA

                          #13
                          Re: No power to KBC after chip change

                          Removed the chip and when I flipped it over I have a bunch of solder bridges between many of the pins. Not sure how I'm gonna clean them up but will report back when I do and resolder chip

                          Comment

                          • ktmmotocross
                            Boardkiller
                            • Feb 2014
                            • 3553
                            • slovakia

                            #14
                            Re: No power to KBC after chip change

                            prefect video how to solder chips. kbc is soldered by drag soldering from 2:00

                            https://www.youtube.com/watch?v=5uiroWBkdFY

                            Comment

                            • p1muserfan
                              Senior Member
                              • Apr 2014
                              • 184
                              • USA

                              #15
                              Re: No power to KBC after chip change

                              Probably a no-no, but even with chip removed there is no power on either side of R2771 (p. 27 upper left)

                              Comment

                              • p1muserfan
                                Senior Member
                                • Apr 2014
                                • 184
                                • USA

                                #16
                                Re: No power to KBC after chip change

                                Originally posted by ktmmotocross
                                prefect video how to solder chips. kbc is soldered by drag soldering from 2:00

                                https://www.youtube.com/watch?v=5uiroWBkdFY
                                Nice!!

                                Comment

                                • p1muserfan
                                  Senior Member
                                  • Apr 2014
                                  • 184
                                  • USA

                                  #17
                                  Re: No power to KBC after chip change

                                  Originally posted by khaahk
                                  Try to pull the gate of q2703 to gnd, that should provide 3v to ec.
                                  Grounding gate of Q2703 did give me 3v to drain and therefore power to the KBC. So what is messed up and causing 3v to go to gate of 2703?

                                  Comment

                                  • khaahk
                                    Badcaps Veteran
                                    • Dec 2013
                                    • 743
                                    • Estonia

                                    #18
                                    Re: No power to KBC after chip change

                                    See if pin 74 on EC is connected to q2705 gate?

                                    Comment

                                    • p1muserfan
                                      Senior Member
                                      • Apr 2014
                                      • 184
                                      • USA

                                      #19
                                      Re: No power to KBC after chip change

                                      Originally posted by khaahk
                                      See if pin 74 on EC is connected to q2705 gate?
                                      Yes, with chip off the board I have continuity between 74 and gate of Q2705

                                      Comment

                                      • khaahk
                                        Badcaps Veteran
                                        • Dec 2013
                                        • 743
                                        • Estonia

                                        #20
                                        Re: No power to KBC after chip change

                                        BQ24707 pin 5 and pin 6 voltages? I think that AC_IN# if pulled low by BQ24707 pin 5, should also pull low the KBC_ON# signal through D2703 opening Q2703.

                                        Comment

                                        Related Topics

                                        Collapse

                                        • Tynan Dill
                                          Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?
                                          by Tynan Dill
                                          I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.

                                          Upon bringing it home and plugging it up, it showed a standby light.

                                          I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.

                                          The screen seems to blackout and stay black, but with a flashlight I can see the display.

                                          With my Playstation 4 connected via HDMI, and running a game I can hear sound.

                                          Assuming...
                                          11-22-2024, 01:46 PM
                                        • acedogblast
                                          Guide to transplant MEC1503 EC chip and EEPROM reprogamming for T14s gen 2 and X13 gen 2
                                          by acedogblast
                                          This is a guide that I am writing for helping others to replace their MEC1503 EC chip if it breaks (or to get around an inconvenient prompt to the BIOS). This forum has been extremely helpful to me so I would like to contribute to help others. I will tell you right now that this task is very difficult to do. You MUST have experience and tools to do precision micro-soldering, BGA reballing, trace repair, and general laptop repair skills.

                                          There are some specialty tools needed to do this task. The replacement MEC1503 chips can be acquired from Aliexpress. Do not buy the bare chips as...
                                          11-02-2024, 05:13 PM
                                        • sam_sam_sam
                                          Desoldering gun station modified to use a 18 volt @ 20 amp switching power supply
                                          by sam_sam_sam
                                          I have wanting to do this project for quite sometime now and I finally found a switching power supply that will work on this desoldering gun station ZD-915 that the original switching power supply took a shit and just was not worth trying to fix it because this switching power is not quite big enough to handle the heater element and the vacuum pump

                                          One note when I tested the switching power supply and the voltage control board I noticed that this desoldering gun heat up much faster than the original switching power supply which I was really surprised by to the point that I might buy...
                                          03-31-2024, 02:12 PM
                                        • eukal
                                          Panasonic toughbook cf-h2 Mk1 no power, 3.3v-5v present but no 3v on bios chip
                                          by eukal
                                          Hello, i have a Panasonic Toughbook Cf-H2 Mk1 that won't power on. The battery charge without problem but no response from the laptop when i press the power button.
                                          I have disassemble and unpluged the cmos battery, same no power on on battery with and whitout the adapter, and only adapter
                                          I have check the voltage i have the main power rail ( +-16v normal for toughbook it's not 19v). I have on the coil after power management chip 3.3v and 5v.
                                          I have check the 3.3v on the power button ribbon cable attach to the motherboard and the voltage go to 0v when i press the button. So...
                                          07-01-2023, 01:00 PM
                                        • Document Archive
                                          HP Pavilion Power Pavilion Power 15-cb009nl Notebook 15 Specification for Upgrade or Repair
                                          by Document Archive
                                          This specification for the HP Pavilion Power Pavilion Power 15-cb009nl Notebook can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the Pavilion Power 15-cb009nl boardview and Pavilion Power 15-cb009nl schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that...
                                          09-06-2024, 05:59 AM
                                        • Loading...
                                        • No more items.
                                        Working...