HP R33 no +VCC_GFX

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  • raajkumar
    Badcaps Veteran
    • Mar 2015
    • 354
    • Srilanka
    #1

    HP R33 no +VCC_GFX

    I checked PU15 (NCP5911) and it has power on
    Pin1 - BST - 4.89V
    Pin2 - PWM - 1.9V
    Pin3 - DRVEN - 4.89V
    Pin4 - VCC - 5.1V
    Pin5 - Low gate - 0v
    Pin6 - GND - 0v
    Pin7 - SW - 0v
    Pin8 - Hi gate - 0v

    Is this OK for this chip?. But i couldn't find any voltage on PL29.
    Attached Files
    Last edited by raajkumar; 06-29-2017, 09:51 PM.
    Tags: None
    • raajkumar
      Badcaps Veteran
      • Mar 2015
      • 354
      • Srilanka
      #2
      Re: HP R33 no +VCC_GFX

      I replaced another chip but i got some different results. There are
      Pin1 - BST - 0V
      Pin2 - PWM - 1.9V
      Pin3 - DRVEN - 1.9V
      Pin4 - VCC - 5.1V
      Pin5 - Low gate - 0v
      Pin6 - GND - 0v
      Pin7 - SW - 0v
      Pin8 - Hi gate - 0v

      So which one is correct. This also not produced any voltages on PL29

        Comment

        • piernov
          Super Moderator
          • Jan 2016
          • 4435
          • France
          #3
          Re: HP R33 no +VCC_GFX

          The new chip isn't soldered properly I think. Anyway what is the resistance between +VIN_VCC_GT and pin 7, and between pin 7 and 6?
          OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

            Comment

            • raajkumar
              Badcaps Veteran
              • Mar 2015
              • 354
              • Srilanka
              #4
              Re: HP R33 no +VCC_GFX

              Originally posted by piernov
              The new chip isn't soldered properly I think. Anyway what is the resistance between +VIN_VCC_GT and pin 7, and between pin 7 and 6?
              +Vin_VCC to Pin7 is 300 Kohms, Pin7 and Pin6 is 200 Ohms

                Comment

                • piernov
                  Super Moderator
                  • Jan 2016
                  • 4435
                  • France
                  #5
                  Re: HP R33 no +VCC_GFX

                  Sounds ok so I would go for a defective/wrongly soldered PU15.
                  OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                    Comment

                    • raajkumar
                      Badcaps Veteran
                      • Mar 2015
                      • 354
                      • Srilanka
                      #6
                      Re: HP R33 no +VCC_GFX

                      Originally posted by piernov
                      Sounds ok so I would go for a defective/wrongly soldered PU15.
                      I replaced PU15 with another one ( I am getting those from scrap boards ) now again it shows

                      Pin1 - BST - 4.89V
                      Pin2 - PWM - 1.9V
                      Pin3 - DRVEN - 4.89V
                      Pin4 - VCC - 5.1V
                      Pin5 - Low gate - 0v
                      Pin6 - GND - 0v
                      Pin7 - SW - 0v
                      Pin8 - Hi gate - 0v

                      But still i cannot find any voltages on PL29

                        Comment

                        • piernov
                          Super Moderator
                          • Jan 2016
                          • 4435
                          • France
                          #7
                          Re: HP R33 no +VCC_GFX

                          Do you have an oscilloscope to check the signal on pin 2 — PWM?
                          OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                            Comment

                            • raajkumar
                              Badcaps Veteran
                              • Mar 2015
                              • 354
                              • Srilanka
                              #8
                              Re: HP R33 no +VCC_GFX

                              Originally posted by piernov
                              Do you have an oscilloscope to check the signal on pin 2 — PWM?
                              I don't have oscilloscope. I checked with 3 chips on PU15.

                                Comment

                                • piernov
                                  Super Moderator
                                  • Jan 2016
                                  • 4435
                                  • France
                                  #9
                                  Re: HP R33 no +VCC_GFX

                                  Maybe the issue comes from PU10 not outputting the right PWM signal. Your issue looks very similar to https://www.badcaps.net/forum/showthread.php?p=754825 even though the board relatively different.
                                  OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                                    Comment

                                    • raajkumar
                                      Badcaps Veteran
                                      • Mar 2015
                                      • 354
                                      • Srilanka
                                      #10
                                      Re: HP R33 no +VCC_GFX

                                      Originally posted by piernov
                                      Maybe the issue comes from PU10 not outputting the right PWM signal. Your issue looks very similar to https://www.badcaps.net/forum/showthread.php?p=754825 even though the board relatively different.
                                      I have doubt on that also. But unfortunately i have only NCP6131 but on this board need to put NCP6132 it is not same. So have to wait until to get new chip.
                                      Last edited by raajkumar; 07-01-2017, 09:03 AM.

                                        Comment

                                        • piernov
                                          Super Moderator
                                          • Jan 2016
                                          • 4435
                                          • France
                                          #11
                                          Re: HP R33 no +VCC_GFX

                                          Unfortunately no, NCP6131 is QFN-52 and NCP6132 is QFN-60 package.
                                          OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                                            Comment

                                            • raajkumar
                                              Badcaps Veteran
                                              • Mar 2015
                                              • 354
                                              • Srilanka
                                              #12
                                              Re: HP R33 no +VCC_GFX

                                              Originally posted by piernov
                                              Unfortunately no, NCP6131 is QFN-52 and NCP6132 is QFN-60 package.
                                              Today i replaced PU15 and checked again. The following results came.

                                              Pin1 - BST - 4.89V
                                              Pin2 - PWM - 0V Change found on here
                                              Pin3 - DRVEN - 4.89V
                                              Pin4 - VCC - 5.1V
                                              Pin5 - Low gate - 5v Change found on here
                                              Pin6 - GND - 0v
                                              Pin7 - SW - 0v
                                              Pin8 - Hi gate - 0v
                                              Last edited by raajkumar; 07-01-2017, 09:15 PM.

                                                Comment

                                                • raajkumar
                                                  Badcaps Veteran
                                                  • Mar 2015
                                                  • 354
                                                  • Srilanka
                                                  #13
                                                  Re: HP R33 no +VCC_GFX

                                                  I solved this problem by Flashed the bios with new. Now the laptop working fine. Thanks Piernov for your ideas and help.

                                                    Comment

                                                    • piernov
                                                      Super Moderator
                                                      • Jan 2016
                                                      • 4435
                                                      • France
                                                      #14
                                                      Re: HP R33 no +VCC_GFX

                                                      Could you write the final measurements before and after BIOS flash? It may help others.
                                                      OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                                                        Comment

                                                        • raajkumar
                                                          Badcaps Veteran
                                                          • Mar 2015
                                                          • 354
                                                          • Srilanka
                                                          #15
                                                          Re: HP R33 no +VCC_GFX

                                                          Originally posted by piernov
                                                          Could you write the final measurements before and after BIOS flash? It may help others.
                                                          Sorry I measured only Hi gate Pin 8. It shows 1.03V and Pin2 ( PWM ) Shows only - 0V. Now i handover the laptop to customer.
                                                          Last edited by raajkumar; 07-02-2017, 06:49 AM.

                                                            Comment

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