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Acer E5-571G Black Screen (a5wah la-b991p)

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    Acer E5-571G Black Screen (a5wah la-b991p)

    Good evening friends of the forum. This laptop has the following problem: it turns on but I get a black screen. Think of a dedicated gpu problem (n15-v-gw-s-a2) Replaced video card but the defect remains. I tried Changing ram, reprogram bios, but nothing. I noticed that the coil pl1203, pl1204 and pl 802 are heating a lot. On pl1203, pl1204 I find the voltage of 1.01V and on pl802 I find 1.80v on one side and on the other I get 0.40v. I suspect this is the integrated graphics in the chipset but I wanted your opinion

    #2
    Re: Acer E5-571G Black Screen (a5wah la-b991p)

    Though i dont have the schematics but i think PL1203/04 is for vcc core and PL802 is GFX core. So the voltage seems to be ok. Are you getting PLT RST??

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      #3
      Re: Acer E5-571G Black Screen (a5wah la-b991p)

      I upload the schematic, https://anonfile.com/k7cfjbkebe/comp...lab991pr10_pdf

      Comment


        #4
        Re: Acer E5-571G Black Screen (a5wah la-b991p)

        measured plt_rst on pin 13 of kbc and result 3,30v

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          #5
          Re: Acer E5-571G Black Screen (a5wah la-b991p)

          Any help please...

          Comment


            #6
            Re: Acer E5-571G Black Screen (a5wah la-b991p)

            You need to measure PU801 voltage on all pins. Pl1203/4 are expected to heat-so nothing to worry there. Since you are getting PLT_Rst means almost all power up seqeunce reuirement are fulfilled.

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              #7
              Re: Acer E5-571G Black Screen (a5wah la-b991p)

              pu801:
              pin 1 1,04v
              pin 2 1,04v
              pin 3 0v
              pin 4 1,04v
              pin 5 1,67v
              pin 6 2,00v
              pin 7 1,74v
              pin 8 0v
              pin 9 1,80v
              pin 10 1,80v
              pin 11 0v
              pin 12 5,04v
              pin 13 7,57v
              pin14 8,14v
              pin 15 8,21v
              pin 16 4,40v
              pin17 0v
              pin18 1,04v
              pin 19 1,04v
              pin 20 1,04

              Comment


                #8
                Re: Acer E5-571G Black Screen (a5wah la-b991p)

                is correct value?

                Comment


                  #9
                  Re: Acer E5-571G Black Screen (a5wah la-b991p)

                  Originally posted by robgerr View Post
                  is correct value?
                  No, the values doesnt seems to be correct. VR oN should be 3.3v . Voltage on pin121 of KBC9022??

                  Comment


                    #10
                    Re: Acer E5-571G Black Screen (a5wah la-b991p)

                    pin 121 3,3v

                    Comment


                      #11
                      Re: Acer E5-571G Black Screen (a5wah la-b991p)

                      So kbc seems to give VR_ON output correctly but still you are having 1.04 at pin1 of PU801. You need to check resistors, caps connected to PU801 and match them with schematic. Is PU801 soldered properly? Any corrosion, missing tracks?? If everything seems good, you can try replacing PU801.

                      Comment


                        #12
                        Re: Acer E5-571G Black Screen (a5wah la-b991p)

                        Good afternoon friends of the forum. I replaced PU801 but the defect remains. on pin 1 of pu801 I find 1.05V. Other suggestion?

                        Comment


                          #13
                          Re: Acer E5-571G Black Screen (a5wah la-b991p)

                          Originally posted by robgerr View Post
                          Good afternoon friends of the forum. I replaced PU801 but the defect remains. on pin 1 of pu801 I find 1.05V. Other suggestion?
                          pls check I/O for liquid damage is common problem on this board

                          Comment


                            #14
                            Re: Acer E5-571G Black Screen (a5wah la-b991p)

                            Unfortunately, in these cases, when attempts are made; problems may increase.
                            Personally, I would try to bring the situation back to its initial state,
                            change the bios with the original, check that there are all the correct voltages and try to reprogram the EC.

                            Comment


                              #15
                              Re: Acer E5-571G Black Screen (a5wah la-b991p)

                              Is it possible to convert UMA removing by PL1201 or not? Do you have any idea to convert discrete to uma by any other method? Thanks in advance.

                              Comment


                                #16
                                Re: Acer E5-571G Black Screen (a5wah la-b991p)

                                can you try? " Acer E5-571G A5WAH LA-B991P Rev 1.0
                                When the solder on the PJ1002 jumper feeding the RAMs on the left side of the GPU is cleaned and the U40 mosfet located on the right side of the GPU is removed, the Nvidia graphics card is disabled. "
                                I'm not happy to be so strong. because it's not humanly

                                Comment


                                  #17
                                  Re: Acer E5-571G Black Screen (a5wah la-b991p)

                                  Hello friends ...got the same motherboard with same issue .
                                  When power on i got a backlight but no picture , i have picture at external .

                                  All the voltages are present , plt_rst too , Vr_on too...but at pin 1 of PU801 got 1.04v.
                                  I also do a uma enable as Post18 mention but same isse.

                                  At lvds connector all voltages are present expect : INVTPWM / DISPOFF# / EDP_HPD = 0v.

                                  Change screen same too

                                  What i must check too !
                                  Thank you

                                  Comment


                                    #18
                                    Re: Acer E5-571G Black Screen (a5wah la-b991p)

                                    Update :

                                    pu801:
                                    pin 1 = VR_ON = 1,052v
                                    pin 2 = PGOOD = 1,052v
                                    pin 3 0v
                                    pin 4 1,052v
                                    pin 5 1,8v
                                    pin 6 2,00v

                                    VR_ON is coming from U1L (CPU) there's a resistor (Not populated) R167 = 1.05v at 2 pads.

                                    The VGATE_3V is coming from U17 (Not populated )
                                    U17 pads
                                    pin 2 = 1.05v
                                    pin 5 = 1.05V
                                    pin 4 = VGATE_3V = 0v

                                    VGATE source !
                                    Last edited by lapfix; 03-02-2022, 06:54 AM.

                                    Comment


                                      #19
                                      Re: Acer E5-571G Black Screen (a5wah la-b991p)

                                      Pu801,pin1 voltage at 1.05v is correct. Have u flashed bios?? What about U43?~

                                      Comment


                                        #20
                                        Re: Acer E5-571G Black Screen (a5wah la-b991p)

                                        Originally posted by mcplslg123 View Post
                                        Pu801,pin1 voltage at 1.05v is correct. Have u flashed bios?? What about U43?~
                                        Thank you my friend.
                                        Since i have a picture at external so i think no need to flash bios !
                                        But i do a clean me and flash new virgin dump , same issue , only external and a backlight at internal as i mention before.

                                        U43 not populated :
                                        1 = not stable = 1.7v or 0.043v or 1.8 with fluctuation at 1 or 0 v
                                        2 = 3v
                                        3 = gnd
                                        4 = 3.2v
                                        5 = 3.3v
                                        Last edited by lapfix; 03-03-2022, 03:20 AM.

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