Sony KDL-19L4000, Delta DPS-70EP, can’t turn on

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • Chungalin
    Badcaps Veteran
    • Jul 2014
    • 422
    • Spain
    #1

    Sony KDL-19L4000, Delta DPS-70EP, can’t turn on

    This Sony KDL-19L4000 doesn't want to turn on.

    PSU (Delta DPS-70EP) has 3.3V standby, but MAIN doesn't rise P_ON to 3.3V in order to activate other voltages. No bad caps. I've disassembled PSU and shorted 3.3V with P_ON. Then other voltages appear (12V and 12V AMP) and nothing seems wrong here.

    Then I notice that AC_OFF line is as low as 0.36V, and I think it should be higher, possibly 3.3V in normal condition. I disconnect only AC_OFF pin from the power connector. Then there's 3.3V at the MAIN side and 0V in PSU side. This way the TV works!

    SM is available at ElektroTanya, but unfortunately, PSU schematic for 19" version is an embedded image in the PDF with VERY LOW resolution, absolutely useless. 26" version looks good, but it's very different.

    Related Photocoupler (NEC PS2561B) has 5.3V between LED pins (Primary side). There's 3.3V at one pin of the phototransistor and 0V at the other pin (that goes to AC_OFF line). I've already tried to replace Photocoupler, to no avail.

    Is there any risk if I leave that AC_OFF disconnected? Great temptation...
    Tags: None
    • budm
      Badcaps Legend
      • Feb 2010
      • 40746
      • USA
      #2
      Re: Sony KDL-19L4000, Delta DPS-70EP, can't turn on

      Yes, I believe it should be more than 3V for normal.
      the AC_OFF is for detecting if the incoming AC to see if it is too high or too low for the TV to operate.
      Never stop learning
      Basic LCD TV and Monitor troubleshooting guides.
      http://www.badcaps.net/forum/showthr...956#post305956

      Voltage Regulator (LDO) testing:
      http://www.badcaps.net/forum/showthr...999#post300999

      Inverter testing using old CFL:
      http://www.badcaps.net/forum/showthr...er+testing+cfl

      Tear down pictures : Hit the ">" Show Albums and stories" on the left side
      http://s807.photobucket.com/user/budm/library/

      TV Factory reset codes listing:
      http://www.badcaps.net/forum/showthread.php?t=24809

        Comment

        • budm
          Badcaps Legend
          • Feb 2010
          • 40746
          • USA
          #3
          Re: Sony KDL-19L4000, Delta DPS-70EP, can't turn on

          This is may be your board diagrams: Delta DPS-70EP-2.

          Pictures of your board?
          Attached Files
          Never stop learning
          Basic LCD TV and Monitor troubleshooting guides.
          http://www.badcaps.net/forum/showthr...956#post305956

          Voltage Regulator (LDO) testing:
          http://www.badcaps.net/forum/showthr...999#post300999

          Inverter testing using old CFL:
          http://www.badcaps.net/forum/showthr...er+testing+cfl

          Tear down pictures : Hit the ">" Show Albums and stories" on the left side
          http://s807.photobucket.com/user/budm/library/

          TV Factory reset codes listing:
          http://www.badcaps.net/forum/showthread.php?t=24809

            Comment

            • dick_barton
              Badcaps Legend
              • Aug 2015
              • 6642
              • Wales
              #4
              Re: Sony KDL-19L4000, Delta DPS-70EP, can't turn on

              You need to check R101-> R106, R124 -> R126 & D107 for AC_Det since that would appear to be the easiest to correct.
              Willing to help but I'm no expert.

                Comment

                • budm
                  Badcaps Legend
                  • Feb 2010
                  • 40746
                  • USA
                  #5
                  Re: Sony KDL-19L4000, Delta DPS-70EP, can't turn on

                  Originally posted by dick_barton
                  You need to check R101-> R106, R124 -> R126 & D107 for AC_Det since that would appear to be the easiest to correct.
                  +1 if that diagram matched your board.
                  BTW, this board does use the CX** IC for the AC_DET, so it only detects if the AC is too low or not.
                  Never stop learning
                  Basic LCD TV and Monitor troubleshooting guides.
                  http://www.badcaps.net/forum/showthr...956#post305956

                  Voltage Regulator (LDO) testing:
                  http://www.badcaps.net/forum/showthr...999#post300999

                  Inverter testing using old CFL:
                  http://www.badcaps.net/forum/showthr...er+testing+cfl

                  Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                  http://s807.photobucket.com/user/budm/library/

                  TV Factory reset codes listing:
                  http://www.badcaps.net/forum/showthread.php?t=24809

                    Comment

                    • Chungalin
                      Badcaps Veteran
                      • Jul 2014
                      • 422
                      • Spain
                      #6
                      Re: Sony KDL-19L4000, Delta DPS-70EP, can't turn on

                      Originally posted by budm
                      This is may be your board diagrams: Delta DPS-70EP-2.
                      Yes! If not, very, very close. Where do you get these schematics??

                      Originally posted by dick_barton
                      You need to check R101-> R106, R124 -> R126 & D107 for AC_Det since that would appear to be the easiest to correct.
                      Yes, it's been one resistor form the "chain" you point: R124, 270KΩ, open. It's not burnt or anything, just open.

                      Replaced and working. AC_OFF is 3.11V now. Thanks for your great help!

                        Comment

                        • budm
                          Badcaps Legend
                          • Feb 2010
                          • 40746
                          • USA
                          #7
                          Re: Sony KDL-19L4000, Delta DPS-70EP, can't turn on

                          Glad to hear it is working, watch out for those high value resistors used in the sensing circuits, they tend to drift up in value or go open circuit. I believe you or may be another person worked on a stereo that I helped you troubleshooting and it has failed sensing resistor as well.
                          ELEKTROTANYA
                          I went to shopjimmy to see what the Delta DPS-70EP is used on, per SJ it shows: Sony A-2670-300-F (DPS-70EP-2) Power Inverter for KDL-22S5500
                          So then I went to ELEKTROTANYA and search for SONY KDL-22S5500.

                          Last edited by budm; 05-02-2016, 03:56 PM.
                          Never stop learning
                          Basic LCD TV and Monitor troubleshooting guides.
                          http://www.badcaps.net/forum/showthr...956#post305956

                          Voltage Regulator (LDO) testing:
                          http://www.badcaps.net/forum/showthr...999#post300999

                          Inverter testing using old CFL:
                          http://www.badcaps.net/forum/showthr...er+testing+cfl

                          Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                          http://s807.photobucket.com/user/budm/library/

                          TV Factory reset codes listing:
                          http://www.badcaps.net/forum/showthread.php?t=24809

                            Comment

                            • dick_barton
                              Badcaps Legend
                              • Aug 2015
                              • 6642
                              • Wales
                              #8
                              Re: Sony KDL-19L4000, Delta DPS-70EP, can't turn on

                              The information regarding the resistors and AC_Det problem was gleamed from reading the many posts here on the Forum.
                              Willing to help but I'm no expert.

                                Comment

                                Previous template Next

                                Related Topics

                                Collapse
                                • Document Archive
                                  MSI Delta DELTA 15 A5EFK-008 Notebook 15 Specification for Upgrade or Repair
                                  by Document Archive
                                  This specification for the MSI Delta DELTA 15 A5EFK-008 Notebook can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the DELTA 15 A5EFK-008 boardview and DELTA 15 A5EFK-008 schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet,...
                                  09-07-2024, 03:40 AM
                                • Abel Bejan
                                  Sony Vaio does not turn on, overheats
                                  by Abel Bejan
                                  Hello,
                                  I am quite noob in advanced electronics, however I'm trying to fix a Sony Vaio PCG-71211M laptop mainly because I love old hardware. I don't want to send it to a technician because this computer is not important for me, I want to fix it as a hobby.
                                  Shortly, this laptop does not display any video output when turned on, no POST, nothing. The keyboard leds are on and I can actually turn Num Locks on and off. Sometimes the laptop turns itself off straight away, sometimes, mostly after some attempts, the laptops enters a loop in which the cpu fan spins very aggressively and the CPU,...
                                  01-11-2025, 10:11 AM
                                • odie34
                                  Sony OLED XR-77A80J - 5 Flashes But Turn On After Hard Reset
                                  by odie34
                                  I am a hobbyist (not a professional) so please be gentle...

                                  I recently received an XR-77A80J that wouldn't turn on. (Repeating 5 flashes when plugged in.)

                                  I did a hard reset by holding the power button for about 30 seconds until the set powered down. I then tried to turn it on and it powered up, bringing me to the setup screen. There's not a lot of detail on the setup screen but the picture didn't have any distortions, so at least a cursory examination suggests no physical damage to the screen. The set appeared to be working normally, but it shut down after about 15 seconds,...
                                  02-18-2024, 09:11 AM
                                • pajdek
                                  Lenovo Y700-17ISK turn on and off
                                  by pajdek
                                  Hello, i have some issues with my laptop Lenovo Y700-17ISK (motherboard BY511 NM-A541), it started when i turn on the laptop, but the lcd wont turn on, i then connected it via hdmi to tv and screen was ok. So i thought maybe lcd stripe is faulty, i removed the bottom cover, disconnected main battery, reset the cmos by disconnecting battery for 1 min, then slighty move the lcd stripe. Conncted power supply and tuned on my laptop, the lcd turn on, it started to load os, then it turn off, after a second it turn on, then after like 3 seconds turn off again, and so on. Removed power supply, waited...
                                  09-20-2023, 02:49 AM
                                • Zetabeta87
                                  Sony KD-49XF809y doesn't turn on
                                  by Zetabeta87
                                  Hi everyone!
                                  I have a 2018 Sony kd 49XF8096 that suddenly stopped turning on: No LED lights up, and it doesn't respond to the power button or the remote control.
                                  The power supply delivers 19.45vand I simply tried to check the fuses on the 2 boards (power and main) but everything seems ok. I have no references on where to test the voltage, but somewhere on the mainboard I also detect some, so you can't to understand which card may be to blame.
                                  Can anyone give me some advice? I haven't found anything online

                                  Thanks so much!!!
                                  4 Photos
                                  11-04-2024, 03:18 PM
                                • Loading...
                                • No more items.
                                Working...