when i turn on, Philliips TV is not on

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  • Nish
    Senior Member
    • Sep 2013
    • 124
    • Canada

    #41
    Re: when i turn on, Philliips TV is not on

    Sorry R_J. It's my mistake I used 12v ground. Also when I fallow your drawing i got 5V.

    The mistake I made. I use negative of C951A and measure then touching the red probe at 12v pins and ground pins so I got 5v all the place.

    Since I fallow your drawing and explanation I got clear. Sorry about that.

    Now I put the 1k resistor CN2: Pin9-1K-pin12 as per your instruction in the post 29.

    I didn't get any voltage at C906 and D903. I am doing the test on bench.

    Comment

    • Nish
      Senior Member
      • Sep 2013
      • 124
      • Canada

      #42
      Re: when i turn on, Philliips TV is not on

      I measure PC902 pin1 red probe and pin 2 black probes and got 0v.

      Do I need to use same ground as standby voltage pin11 on the CN2?
      Last edited by Nish; 01-13-2020, 10:22 AM.

      Comment

      • R_J
        Badcaps Legend
        • Jun 2012
        • 9515
        • Canada

        #43
        Re: when i turn on, Philliips TV is not on

        The voltage that supplies PC902 comes from the AL+5V and connects to Q910 emitter. Q910 must be switched on by Q905 to supply the AL+5V to the collector and then to PC902, pin1

        This Philips POS service manual sucks and blows. If you look CN2 on Page 43, then look at page 42 CN3002 (this is where they connect together) it gets even more confusing. They swap the wires around so maybe pin 11(5vground) connects to the 12v ground at the main board?
        Attached Files
        Last edited by R_J; 01-13-2020, 11:31 AM.

        Comment

        • Nish
          Senior Member
          • Sep 2013
          • 124
          • Canada

          #44
          Re: when i turn on, Philliips TV is not on

          Originally posted by R_J
          The voltage that supplies PC902 comes from the AL+5V and connects to Q910 emitter. Q910 must be switched on by Q905 to supply the AL+5V to the collector and then to PC902, pin1

          This Philips POS service manual sucks and blows. If you look CN2 on Page 43, then look at page 42 CN3002 (this is where they connect together) it gets even more confusing. They swap the wires around so maybe pin 11(5vground) connects to the 12v ground at the main board?
          Yes it is confusing. I measured voltage Q910, Q905 has 4.48v and PC902 pin1 and 2 has 4.48v. Something short or I am using wrong ground. I am using negative lead of C951A as my ground.

          Comment

          • Nish
            Senior Member
            • Sep 2013
            • 124
            • Canada

            #45
            Re: when i turn on, Philliips TV is not on

            Q910, Q905 all 3 pin has 4.48v.

            Comment

            • Nish
              Senior Member
              • Sep 2013
              • 124
              • Canada

              #46
              Re: when i turn on, Philliips TV is not on

              I want to remove the Q905, but I have still 4.48. While i unsolder it wonot effect any other parts.

              Comment

              • R_J
                Badcaps Legend
                • Jun 2012
                • 9515
                • Canada

                #47
                Re: when i turn on, Philliips TV is not on

                What are you using for ground when you measure this voltage? Q905 emitter is connected to ground so use it to check the voltages in that area. AGAIN, the AL+5V does NOT use the same ground as the rest of the circuit. so stop using C951A as ground.

                If you want the AL+5V or C951A to have the same ground you need to connect pin 11 to pin 5,6,7,8 Or add the jumper wire J14 next to CN2, Just remember to remove J14 after testing the power supply.
                Last edited by R_J; 01-13-2020, 12:32 PM.

                Comment

                • Nish
                  Senior Member
                  • Sep 2013
                  • 124
                  • Canada

                  #48
                  Re: when i turn on, Philliips TV is not on

                  Originally posted by R_J
                  What are you using for ground when you measure this voltage? Q905 emitter is connected to ground so use it to check the voltages in that area. AGAIN, the AL+5V does NOT use the same ground as the rest of the circuit. so stop using C951A as ground.

                  If you want the AL+5V or C951A to have the same ground you need to connect pin 11 to pin 5,6,7,8 Or add the jumper wire J14 next to CN2, Just remember to remove J14 after testing the power supply.
                  Sorry about it. I have 0V around that are.

                  Comment

                  • R_J
                    Badcaps Legend
                    • Jun 2012
                    • 9515
                    • Canada

                    #49
                    Re: when i turn on, Philliips TV is not on

                    Since you now have the AL+5V, why not install it in the tv and see if it works?

                    Comment

                    • Nish
                      Senior Member
                      • Sep 2013
                      • 124
                      • Canada

                      #50
                      Re: when i turn on, Philliips TV is not on

                      Originally posted by R_J
                      Since you now have the AL+5V, why not install it in the tv and see if it works?
                      I did, standby light blinking. I measure standby voltage. It becomes 1.8v not 4.48v.

                      Comment

                      • R_J
                        Badcaps Legend
                        • Jun 2012
                        • 9515
                        • Canada

                        #51
                        Re: when i turn on, Philliips TV is not on

                        That could mean one of two things, there is a problem on the main board killing the 5 volts or the power supply can't supply enough current.
                        Is that measuring the standby voltage from ground to CN2 pin9 or across +&- of C951A. You could also check the standby voltage between pin9 and 11 on CN2
                        The AL+5V feeds 2 voltage regulators IC3601(+1.25v) and IC3606(+3.3v) (page37) maybe one of them is bad?
                        The one ic supplies 450ma and the other 200ma, so the power supply should be able to supply at least 1 amp. So you can try placing a 10ฮฉ 2~5 watt resistor across the standby supply (or across C951A) This will draw about 500ma. and should not drop the 5 volts. If it does drop, then the power supply is at fault.
                        Last edited by R_J; 01-14-2020, 08:14 PM.

                        Comment

                        • Nish
                          Senior Member
                          • Sep 2013
                          • 124
                          • Canada

                          #52
                          Re: when i turn on, Philliips TV is not on

                          Originally posted by R_J
                          That could mean one of two things, there is a problem on the main board killing the 5 volts or the power supply can't supply enough current.
                          Is that measuring the standby voltage from ground to CN2 pin9 or across +&- of C951A. You could also check the standby voltage between pin9 and 11 on CN2
                          The AL+5V feeds 2 voltage regulators IC3601(+1.25v) and IC3606(+3.3v) (page37) maybe one of them is bad?
                          The one ic supplies 450ma and the other 200ma, so the power supply should be able to supply at least 1 amp. So you can try placing a 10ฮฉ 2~5 watt resistor across the standby supply (or across C951A) This will draw about 500ma. and should not drop the 5 volts. If it does drop, then the power supply is at fault.
                          Sorry to say I have only 0 017v at C951A, before I solder the resistor.

                          Comment

                          • R_J
                            Badcaps Legend
                            • Jun 2012
                            • 9515
                            • Canada

                            #53
                            Re: when i turn on, Philliips TV is not on

                            So NOW you don't have the standby AL5V any more?

                            Comment

                            • Nish
                              Senior Member
                              • Sep 2013
                              • 124
                              • Canada

                              #54
                              Re: when i turn on, Philliips TV is not on

                              Originally posted by R_J
                              So NOW you don't have the standby AL5V any more?
                              No I don't have the standby voltage at C951A. But I have 5v at ZD907

                              Comment

                              • R_J
                                Badcaps Legend
                                • Jun 2012
                                • 9515
                                • Canada

                                #55
                                Re: when i turn on, Philliips TV is not on

                                from post #41
                                Also when I fallow your drawing i got 5V
                                So you never did have this voltage?

                                Also:
                                I did, standby light blinking. I measure standby voltage. It becomes 1.8v not 4.48v.
                                Where is this voltage coming from if you do not have standby voltage?
                                Attached Files
                                Last edited by R_J; 01-16-2020, 10:27 AM.

                                Comment

                                • Nish
                                  Senior Member
                                  • Sep 2013
                                  • 124
                                  • Canada

                                  #56
                                  Re: when i turn on, Philliips TV is not on

                                  Originally posted by R_J
                                  from post #41 So you never did have this voltage?

                                  I had this voltage before I put it in tv and connected t mainboard. After this now I do not have it.

                                  Also: Where is this voltage coming from if you do not have standby voltage?
                                  I solder 2 wire at C915A and measure.

                                  Now I removed from tv and measuring the voltage at C915A.

                                  Comment

                                  • R_J
                                    Badcaps Legend
                                    • Jun 2012
                                    • 9515
                                    • Canada

                                    #57
                                    Re: when i turn on, Philliips TV is not on

                                    Originally posted by Nish
                                    I solder 2 wire at C915A and measure.

                                    Now I removed from tv and measuring the voltage at C915A.
                                    So do you have the standby +5 volts?

                                    Comment

                                    • Nish
                                      Senior Member
                                      • Sep 2013
                                      • 124
                                      • Canada

                                      #58
                                      Re: when i turn on, Philliips TV is not on

                                      Originally posted by R_J
                                      So do you have the standby +5 volts?
                                      I donot have 5V at C951A

                                      Comment

                                      • Nish
                                        Senior Member
                                        • Sep 2013
                                        • 124
                                        • Canada

                                        #59
                                        Re: when i turn on, Philliips TV is not on

                                        I have 5v from IC901 to ZD907
                                        Attached Files
                                        Last edited by Nish; 01-16-2020, 01:09 PM.

                                        Comment

                                        • R_J
                                          Badcaps Legend
                                          • Jun 2012
                                          • 9515
                                          • Canada

                                          #60
                                          Re: when i turn on, Philliips TV is not on

                                          Originally posted by Nish
                                          I have 5v from IC901 to ZD907
                                          So you think that just because you have 5 volts on ZD907 you should have 5 volts for to supply the main board? Have another look at the schematic.
                                          in post #50 you said:
                                          I did, standby light blinking. I measure standby voltage. It becomes 1.8v not 4.48v.
                                          Where is this voltage coming from???????
                                          Last edited by R_J; 01-16-2020, 01:18 PM.

                                          Comment

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