HP Pavillion Laptop model 15 ab292nr no picture , Boots & Runs?

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • computersbyterry
    New Member
    • Mar 2020
    • 4
    • United States
    #1

    HP Pavillion Laptop model 15 ab292nr no picture , Boots & Runs?

    I have an HP Pavillion Laptop model 15 ab292nr.

    I have submitted 2 pictures
    These are the details from picture 1
    The laptop will turn on the fan spins but no picture on the screen. The power supply unit and screen is fine. When the charger is plugged in the charging light comes on. When the power button is pressed the power light comes on and stays on. First Mosfet there is 19.5V, on both sides (where power comes in and goes out)the Gate is 17.8v. Second Mosfet comes in at 19.5V and leaves at 19.5V the Gate is 25.5v. Next the fuze is fine with 19.5v both sides. Third Mosfet there is 19.5v (*these readings were the same on a simular board that works) on the output the Source is 0.86v and the Gate is 0.89v. There is what looks to be a large resistor (PJ531K 1V) tied to the second mosfet there is 19v in and 0v out.

    These are the details from picture 2
    The far side of the 19v power rail seems ok at the test point, so I think the 19 volt power rail is fine. The BIOS readings are as follows
    (the power button has to be pressed and the motherboard on to get the readings).

    BIOS pins
    1-3 - 3.3v
    4 - 0v
    5-6 - 0v
    7-8 - 3.3v

    I really would appreciate to connect with anyone who has some knowledge about these laptop power circuits and get some input. Any advice would be appriecated.
    Attached Files
    Last edited by computersbyterry; 03-05-2020, 06:54 PM.
    Tags: None
    • mcplslg123
      Badcaps Legend
      • Jun 2015
      • 7262
      • india
      #2
      Re: HP Pavillion Laptop model 15 ab292nr no picture , Boots & Runs?

      The measurement from pic1 is fine. Are you sure mb is posting?? Numlock glows on usb kbd?? If so, you need to measure LVDS/EDP pins for voltage. Do you get display on ecternal monitor?

        Comment

        • ttallos
          New Member
          • Oct 2019
          • 2
          • United States
          #3
          Re: HP Pavillion Laptop model 15 ab292nr no picture , Boots & Runs?

          Thank you for your reply and help! I will measure LVDS/EDP pins for voltage. I have been thinking the GPU is bad because all the voltages look right everywhere. I will get back to you when I can get the time to check things out. Thanks for the help!

            Comment

            • ttallos
              New Member
              • Oct 2019
              • 2
              • United States
              #4
              Re: HP Pavillion Laptop model 15 ab292nr no picture , Boots & Runs?

              No display on external monitor. I stuck a good board in this machine and everything works so I know its the motherboard

                Comment

                Previous template Next

                Related Topics

                Collapse
                • Jane
                  How do you test MOSFET in laptops ?
                  by Jane
                  I tried to use this method:

                  Testing an N-channel MOSFET:

                  Step 1: Discharge the Gate (turn off the MOSFET)
                  Place the black probe (COM) on the Source (S) and the red probe on the Drain (D). The multimeter should show no continuity (high resistance or "OL" – open line).
                  Then, touch the black probe to the Source (S) and the red probe to the Gate (G). This discharges any stored charge in the Gate, turning the MOSFET off.

                  Step 2: Charge the Gate (turn on the MOSFET)
                  Now, place the red probe on the Gate (G) and the black probe on the                  ...
                  09-27-2024, 03:31 AM
                • Tr0ll
                  T-con suspect issue. Both ribbon cables no picture. One ribbon cable ok. (58pus8545)
                  by Tr0ll
                  Hi guys! I realized you have a lot of knowledge here so i am hoping you could point me in right direction with my odd issue.

                  The Tv is a Philips 58PUS8545/12, it had no picture but working backlights.

                  Original T-con:
                  Opened the Tv and tested to unplug one ribbon cable at a time. With this test i could see that i got fine picture on both halves as long as there was only one ribbon cable connected, with two connected picture were gone.

                  First replacement T-con:

                  I thought it might be t-con and ordered new t-con from china(supposedly tested)...
                  10-07-2023, 07:48 PM
                • Nooy
                  VGA MOSfet permanently shorted and loss of MOSfet pad
                  by Nooy
                  Hello everyone, I recently found this badcaps site and super Learn Electronics Repair youtube channel. And I wanted to learn how to troubleshoot power supplies and VGA cards and how to practice soldering, since I already have a properly defective piece of them. I am currently trying to solve two problems:

                  I have a Gigabyte GV-RX460WF2OC-4GD type card. I managed to find the faulty MOSfet (AON6414A) on it, which I replaced. The card starts up, but after about half a minute, the MOSfet in the same position will be shorted again. Is it possible that the PWM controller driving the MOSfet...
                  02-14-2024, 02:26 AM
                • JJAAMM
                  SAMSUNG UN55KS9000F picture fades then distorts into vertical lines after 20 seconds
                  by JJAAMM
                  This was my main TV for the last 6 years. I'm not inclined to throw out a $2600 TV so quickly so I'm trying to investigate the issue.

                  Problem
                  TV was disconnected from power for 6 months during construction. When I plugged it yesterday picture was fine, after 30 seconds it dimmed then started developing horizontal lines, picture then starts to ghost vertically until it degrades into vertical streaks. TV always displays a perfect picture when cold. I can unplug TV for 5 minutes and plug it back in and picture is restored for 20 seconds. I can also keep it in standby mode...
                  07-06-2023, 06:01 AM
                • TR103
                  Samsung TV model UE50TU: rebooting, backlight, sound, but no picture
                  by TR103
                  Hi, I have a Samsung UE50TU with:
                  - sound and backlight, but no picture
                  - when it arrived, it had a picture for a few seconds
                  - it keeps rebooting
                  - without ribbon cable between the two panel boards, it does not reboot but I have no picture
                  - without cable between mainboard and lcd panel, it does not reboot (but obviously i have no picture)
                  - when i try a tape fix, its keeps rebooting, unless I tape off pin 1 (the innermost pin). In that case it does not reboot but I have no picture.

                  - without cable between mainboard and lcd panel and with a jumpered...
                  01-22-2025, 04:12 PM
                • Loading...
                • No more items.
                Working...