Insignia NS-48D510NA15 No Standby

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • neilc6
    Badcaps Legend
    • Nov 2015
    • 1550
    • Canada

    #1

    Insignia NS-48D510NA15 No Standby

    This model suffers from bad backlights but my power supply is dead and no standby light and no standby voltage. Main fuse was good but found U807 (NCH, 650V, 8A) shorted and replaced it (subbed with 450V). Didn't fix it. Checked C822 and measures 100pF. Main filter cap is around 290V and drifting a few volts. Suspecting PFC IC may have been damaged. Only one set of wires to strips (10 rows of 6 LEDs) and reading about 60V on LED tester so not sure if there are bad LEDs as well. May or may not be related.

    Power supply is HLL-4855WC (186132 according to Shopjimmy)
    Attached Files
  • R_J
    Badcaps Legend
    • Jun 2012
    • 9535
    • Canada

    #2
    Re: Insignia NS-48D510NA15 No Standby

    If U807 was shorted, Is R818 still ok? The circuit does seem to be working as the pfc circuit is sort of working.
    I would then check the voltage on C819 (20v), C817 (16v) and C811 (16v) C819 47µf/50v would be my first suspect.
    If one or all of those caps are bad, the vcc for the ic's will not be stable.
    You might also want to check VD807, VD808 & VD812.
    Last edited by R_J; 03-08-2020, 06:25 PM.

    Comment

    • neilc6
      Badcaps Legend
      • Nov 2015
      • 1550
      • Canada

      #3
      Re: Insignia NS-48D510NA15 No Standby

      Originally posted by R_J
      If U807 was shorted, Is R818 still ok? The circuit does seem to be working as the pfc circuit is sort of working.
      I would then check the voltage on C819 (20v), C817 (16v) and C811 (16v) C819 47µf/50v would be my first suspect.
      If one or all of those caps are bad, the vcc for the ic's will not be stable.
      You might also want to check VD807, VD808 & VD812.
      R818 tests ok and not open. C819 bouncing between 0 and 50V. C817 is at 15V for a few seconds, drops out and cycle repeats. C811 cant find. I will pull off those two caps and test out of circuit tomorrow. The 3 diodes test fine.

      I believe the 60 LEDs are one big string so expected voltage is around 160V with the LED tester. That is a lot of shorted out ones which likely took out the power supply.

      Comment

      • neilc6
        Badcaps Legend
        • Nov 2015
        • 1550
        • Canada

        #4
        Re: Insignia NS-48D510NA15 No Standby

        Tested C819 and C817 out of circuit and they are both good. I have ordered a new PS board. Appears to have two different strips for this model HD480DF-B37 or HD480DF-B32 with different lens spacing.

        Comment

        • R_J
          Badcaps Legend
          • Jun 2012
          • 9535
          • Canada

          #5
          Re: Insignia NS-48D510NA15 No Standby

          It is unlikely the led's took out the power supply, the led circut has ovp and ocp to shut it down. When you checked those cap voltages , did you check if there was any +12v or +14v on the XP805 plug? also was the main board connected?

          Comment

          • neilc6
            Badcaps Legend
            • Nov 2015
            • 1550
            • Canada

            #6
            Re: Insignia NS-48D510NA15 No Standby

            I opened up the panel to check the LED strips and they were all good. The black wire is positive and the white wire is negative and the tester measured 60V reverse biased. My tester is a little flakey and didn't give a reading when biased correctly. I did confirm the LEDs are all wired in series.

            The connector voltages were checked with the main board plugged in. The capacitor voltages were checked on the bench with nothing plugged in.

            Comment

            • R_J
              Badcaps Legend
              • Jun 2012
              • 9535
              • Canada

              #7
              Re: Insignia NS-48D510NA15 No Standby

              But are you getting ANY voltage on the +12 or +14 volt output?
              With the board on the bench (no main connected) it will just be in standby. so ic N834 will be soft/skip mode
              I can only assume there is +14volts on XP805, so connect a 1K resistor retween the +14v and the STB pin. This will turn on the power supply.
              Tha fact you were getting between 0~50v on C819 tells me you should also have the +14 volts on C856 (or xp805 pin 9,10).

              C811 is a small elec. cap. between the a/c input and v802. It is the VCC cap for the PFC ic.
              Last edited by R_J; 03-09-2020, 05:30 PM.

              Comment

              • neilc6
                Badcaps Legend
                • Nov 2015
                • 1550
                • Canada

                #8
                Re: Insignia NS-48D510NA15 No Standby

                I got a similar power supply HLL-4255WJ for Sharp LC-40N5000U and it had a shorted U807 FET and visible damage on R818 (blown). I replaced both and plugged it in and one leg of C822 blew as well as N834. Replaced those two and now power supply is working but searching N834 found this thread and dug up this old board in my junk pile.

                Comparing boards, I found R808, R811 and R813 damaged on this board so replaced these 3 as well as N834 and still no standby. Found the schematic posted by RJ in another thread searching N834 so can see if I can track it down further. PFC voltage is a stable 155V.
                Attached Files

                Comment

                • neilc6
                  Badcaps Legend
                  • Nov 2015
                  • 1550
                  • Canada

                  #9
                  Re: Insignia NS-48D510NA15 No Standby

                  I compared my working board with the Insignia and the standby voltage is low
                  PFC = 159V (same for both)
                  20V (C819) 6.5V on the Insignia, 18.5V for the Sharp
                  VDD (C817) 8-10V unstable, 15V for the Sharp

                  Since the 20V is coming directly from the transformer not sure what is causing the low voltage. Checked R820, VD805, R821, R823, VD825 and C807.
                  Last edited by neilc6; 07-09-2020, 04:24 PM.

                  Comment

                  Related Topics

                  Collapse

                  • Pipolups
                    Corsair K70 LUX RGB dying LEDs
                    by Pipolups
                    Hi there !

                    I'm having an issue for several weeks with my quite old K70 LUX RGB keyboard. I haven't used it for few months, and once I setup up again my desktop computer, I got several dead LEDs on that keyboard. I tried the Corsair troubleshooting thing (disabling options in iCUE, ...) but nothing changed so I conclude that for some reason some LEDs went in retirement...😅
                    Decision taken to change these LEDs as I have access to desoldering iron and binocular magnifier, I wrote a ticket to tech support, hopping to obtain the LEDs reference and... They refused to tell me 🙄...
                    10-08-2024, 11:58 AM
                  • valvashon
                    Insignia NS-LCD19-09 no standby LED; (new problem)
                    by valvashon
                    Having a new problem with the 19" Insignia that I modified with one of my automatic turn on circuits. That is now completely disconnected so that is not the issue. I was doing some modifications on that circuitry and managed to short something out on the underside of the power board.
                    Actually found and bought the service manual (who knew it was even available?!) which brought me to the High Voltage Startup Circuit controller chip.
                    Looking up that chip number- LD7575APS brought me to the attached datasheet. I have marked my voltage readings on the schematic sheet (open in new...
                    08-30-2023, 10:41 AM
                  • tvguy12012012120
                    Zombie Samsung UN55NU6900F dead / no standby voltage - randomly came to life after hours of troubleshooting then died
                    by tvguy12012012120
                    This is my first attempt at troubleshooting a board like this, I know I could just buy a new board but I'm curious to figure out how this works. I've been testing different components in the evenings this week and I think the problem is with the IC failing to start up for some reason. When the board is plugged in there is no standby voltage.

                    Then today it randomly sprung to life like a zombie but shortly died thereafter. I have no idea why it would have done that and its the first time I've seen it running. I discharged capacitors on the board last night, then it was sitting today....
                    02-07-2025, 05:13 PM
                  • ngth82
                    Modifying Insignia NS-55D510NA17 SMPS for lower current LEDs
                    by ngth82
                    Good morning bad caps -

                    I have an Insignia NS55D510NA17 TV that I bought for $20. The there are 50 backlights in the TV and 48 or so are BLUE and this appears to be due to the yellow film/coating breaking down on each individual LED. (See picture; camera picks this up as purple... they are really blue). The LED itself looks to be an exposed die. There is no plastic package for them. I couldn't find much information about the LEDs or a direct discrete replacement either. These come from the LED strip - SVH550AC3_5LED_REV05_150410.

                    Anyway, I would like to replace...
                    03-08-2020, 12:44 PM
                  • fharris1977
                    Vizio D50u-D1 Dead Set No Standby
                    by fharris1977
                    Hi. I got a Vizio with no power or standby, and won't turn on with remote or button. I checked the voltages on the connector and all read 0.00V or nearly 0(0.050 ON/OFF pin). None of the pins are labeled STB for standby although I do see some 5V pins. Other than the obvious standby led, which isn't coming on, is there a way to check for standby voltage on this PS. I'm trying to see if my problem is the PS or mainboard. Some Vizios I have fixed with no standby led me to think it was the PS but it turned out being the mainboard. Any experience with this set would be greatly appreciated.
                    12-28-2023, 10:25 AM
                  • Loading...
                  • No more items.
                  Working...