HP 6735B dead, no power

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • rtstorm
    Badcaps Veteran
    • Feb 2012
    • 971
    • Croatia

    #1

    HP 6735B dead, no power

    hello, i have this laptop with no sign of life. I find that 19V wont pass Q500 mosfet. I have 19V on pin 1,2,3 and 4 and 0V on 5,6,7,8.

    It is a P-channel mosfet so the gate need to be lower. I check ADP_EN# a it lead me to U17 (AS393MTR_E1)

    U17 have:

    pin1 - 0V
    pin2 - 6V
    pin3 - 0V
    pin4 - 0V
    pin5 - 5V
    pin6 - 0V
    pin7 - 19.9V
    pin8 - 19.9V
    ...the quieter you become the more you are able to hear...
  • rtstorm
    Badcaps Veteran
    • Feb 2012
    • 971
    • Croatia

    #2
    Re: HP 6735B dead, no power

    please tell me what 'LIMITsignal' stand for on DC jack?
    ...the quieter you become the more you are able to hear...

    Comment

    • khaahk
      Badcaps Veteran
      • Dec 2013
      • 759
      • Estonia

      #3
      Re: HP 6735B dead, no power

      It must be around 7V from adapter - do you have original working adapter? The other way is to use 350k resistor from 19v to limit signal, it should provide also about 7V to the pin. Otherwise mainboard will not detect adapter present.

      Comment

      • rtstorm
        Badcaps Veteran
        • Feb 2012
        • 971
        • Croatia

        #4
        Re: HP 6735B dead, no power

        ok i put 350k between DC in (19V) and Signal limit and laptop worked. Should i leave that? Is this DC jack have 350k build in so the connection broke?
        ...the quieter you become the more you are able to hear...

        Comment

        • khaahk
          Badcaps Veteran
          • Dec 2013
          • 759
          • Estonia

          #5
          Re: HP 6735B dead, no power

          Most likely the power adapter does not work. (or the center pin is disconnected).

          Comment

          • gcomputers
            Badcaps Veteran
            • Apr 2013
            • 509
            • Albania

            #6
            Re: HP 6735B dead, no power

            Originally posted by rtstorm
            ok i put 350k between DC in (19V) and Signal limit and laptop worked. Should i leave that? Is this DC jack have 350k build in so the connection broke?
            please can you share any pic?

            Comment

            • rtstorm
              Badcaps Veteran
              • Feb 2012
              • 971
              • Croatia

              #7
              Re: HP 6735B dead, no power

              Here is the pic of DC jack from both side.
              Attached Files
              ...the quieter you become the more you are able to hear...

              Comment

              • rtstorm
                Badcaps Veteran
                • Feb 2012
                • 971
                • Croatia

                #8
                Re: HP 6735B dead, no power

                what voltage should i have on center pin (needle) of charger? I have 0V on that needle
                ...the quieter you become the more you are able to hear...

                Comment

                • rtstorm
                  Badcaps Veteran
                  • Feb 2012
                  • 971
                  • Croatia

                  #9
                  Re: HP 6735B dead, no power

                  when i use non HP charger (universal) laptop is working.
                  ...the quieter you become the more you are able to hear...

                  Comment

                  • khaahk
                    Badcaps Veteran
                    • Dec 2013
                    • 759
                    • Estonia

                    #10
                    Re: HP 6735B dead, no power

                    When adapter not connected - approx 19V
                    When connected - 7-7.5V
                    The center pin's wire is most likely broken.

                    Comment

                    Related Topics

                    Collapse

                    • double_DD
                      How can I be sure that my EC chip is dead?
                      by double_DD
                      Hi all,

                      As the title suggests, how can I be sure that my EC chip is really dead?

                      I've recently gotten into this hobby of laptop repairs, and have successfully brought back to life a couple with some easy fixes, mostly shorted caps.

                      Now I'm working on HP Probook 455 G8, that had some "devil" run around on 3V line, burning a bunch of stuff. Luckily I have a dead 455G7 (for spare parts) so I managed to fix it (swapped burned parts) to a point that it will charge (both on barrel jack and usb-c), but it doesn't want to turn on. There is a 3V3 on a keyboard...
                      03-12-2025, 07:47 AM
                    • disorder
                      ps5 edm-033 dead after hdmi/usb ports destroyed
                      by disorder
                      hello guys,

                      i need help to repair a edm-033 ps2
                      history : as always hdmi port and usb ports destroyed after unplugged
                      after change them, ps5 dead too : 1 beep, no blue light. after inspection 1.8v power was shorted, and because of dead panasonic chip. after remove it : no short anymore
                      so i changed it
                      now i have got 5v stby,, 3.3v stby, 3.3v power, 1.8v power and no short on them
                      but the ps5 is dead again : 1 beep, near 10 seconds with power lines and then off, no blue light ...

                      i don't see any projection of liquid metal on pcb.
                      ...
                      01-14-2025, 12:48 PM
                    • Beton
                      Finding a dead short component
                      by Beton
                      Hi guys!
                      I searched for the term "dead short" in the forum but no specific thread came up however if I'm just blind and couldn't see the thread talking about this please forward me to that direction.
                      So my problem is I don't know how to find the source of a dead shorted voltage rail. Dead short = ~0 ohm resistance.
                      I have two VGAs (HD 4850 and HD 4870), both dead shorted to ground on the memory rail. I have the boardview file for the 4870 and the memory rail consists around ~7892346 capacitors...
                      I have a bench PSU and if I try to inject voltage the voltage...
                      12-10-2021, 01:05 PM
                    • zunasthegreat
                      Chieftec GPS-450-AA with dead 20N60C3
                      by zunasthegreat
                      Hello everyone hope all doing well!
                      I have this PSU (GPS450-AA delta oem) around for like 4-5 years and I had it recapped early 2020 or 2021 with mostly UCC KY and Nichicon PW's. The bulk was and still is fine, the original Ltec's were bloated and empty. The previous issue was some major coil whine noise and at times random shutdowns when going idle. Today it started tripping the mains breaker and I think I have dead APFC mosfets (20N60C3). Right now upon checking I have the Q1 and Q3 FETs dead so far and I guess those are responsible for the PFC circuit. The only thing I care is If there...
                      09-01-2024, 07:12 PM
                    • FiguringITout
                      MSI Raider GE75 - Not posting, probable dead CPU
                      by FiguringITout
                      Hello, today I'm working on this lovely MSI Raider GE75 gaming laptop which I bought to flip. Unfortunately, I believe the CPU is toast but I wanted a second opinion before I chucked it into my spare parts bin. I will not have most tools with me today as I'm away from my workbench but I have the basics (a good multimeter, a horrible iron, a solid screwdriver, and my trusty thermal cam). I do not have the original 230w charger, but I have a Dell 180w which was sold with the device and reportedly "worked fine for them".

                      Specs: I7-10750H, RTX 2060, 32GB RAM (unknown manufacturer)...
                      07-25-2024, 07:27 AM
                    • Loading...
                    • No more items.
                    Working...