e701i-a3 no picture but backlights

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • tjmethod
    Senior Member
    • Jun 2013
    • 137
    • United States

    #61
    Re: e701i-a3 no picture but backlights

    Originally posted by freakaftr8
    Well is there a short showing up in the COXA transistor?
    Hey there freak new new magic transistors are in and I only had time yesterday to replace the one's on the 2 of the 3 t-cons I have the 3rd one is still in the tv. I recall, you had replaced your COXA with one of these from a Sony t-con that you had and the values are higher and they handle more power from your and is what has been working without issue on one of your 70's? I will be doing g so e testing later today- I had a hell of a time resolder the new ones in place. Just positoning was a task and a magnifying glass is a must! I even added a tiny bit of solder but wasn't easy even though I sharpened the tip with a dremel. I'm crossing my fingers
    Attached Files

    Comment

    • tom66
      EVs Rule
      • Apr 2011
      • 32560
      • UK

      #62
      Re: e701i-a3 no picture but backlights

      If you're talking about sharpening the tip of your soldering iron with a dremil, that pretty much destroys the tip as that has a fine alloy layer that allows the iron to work properly. You'd best just get a new tip, they're not very expensive anyway (a few dollars a piece in most cases.) And that way you can get the right size tip, I prefer using an angled flat tip.
      Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
      For service manual, schematic, boardview (board view), datasheet, cad - use our search.

      Comment

      • freakaftr8
        Badcaps Legend
        • Oct 2012
        • 3743
        • USA

        #63
        Re: e701i-a3 no picture but backlights

        Good deal. Just remember to to test tcon board without either ribbon connected to the output just the LVDS cable connected first to verify proper working voltages before you proceed
        Did I leave the soldering iron on?

        Comment

        • tjmethod
          Senior Member
          • Jun 2013
          • 137
          • United States

          #64
          Re: e701i-a3 no picture but backlights

          Originally posted by tom66
          If you're talking about sharpening the tip of your soldering iron with a dremil, that pretty much destroys the tip as that has a fine alloy layer that allows the iron to work properly. You'd best just get a new tip, they're not very expensive anyway (a few dollars a piece in most cases.) And that way you can get the right size tip, I prefer using an angled flat tip.
          Thanks Tom- I actually bought a 60 watt iron thats got adjustable dial that had a sharp tip but it wasnt sharp enough as the one I sharpened which does work anyway but I'm sure you're totally right. I have no formal training in soldering other than past experience. My problem is being able to see the damn things since they're so small

          Comment

          • vinceroger69
            Badcaps Legend
            • Mar 2012
            • 6714
            • uk

            #65
            Re: e701i-a3 no picture but backlights

            Originally posted by tjmethod
            Hey there freak new new magic transistors are in and I only had time yesterday to replace the one's on the 2 of the 3 t-cons I have the 3rd one is still in the tv. I recall, you had replaced your COXA with one of these from a Sony t-con that you had and the values are higher and they handle more power from your and is what has been working without issue on one of your 70's? I will be doing g so e testing later today- I had a hell of a time resolder the new ones in place. Just positoning was a task and a magnifying glass is a must! I even added a tiny bit of solder but wasn't easy even though I sharpened the tip with a dremel. I'm crossing my fingers
            in the first picture of the tcon under the number 163 by the big chip pins theres a blob of solder that maybe shorting some pins out just make sure you remove it before powering it on.

            Comment

            • tjmethod
              Senior Member
              • Jun 2013
              • 137
              • United States

              #66
              Re: e701i-a3 no picture but backlights

              Originally posted by freakaftr8
              Good deal. Just remember to to test tcon board without either ribbon connected to the output just the LVDS cable connected first to verify proper working voltages before you proceed
              Well I found the ohm meter that I was using crapped out even thought the battery and fuze were good so I bought a new digitial multi meter. I tested a couple 1.5 AA batteries- one new and one not new but good. The readings were around 1567 on the new one and 1534 on the other. I got all 3 t-cons suited up with the new QF transistors. With each board hooked up, then the LVDS cables hooked up only, then the power cable plugged in and they all read the same. In ohm mode with the dial on 200k with the negative probe on the left middle single leg and the red probe on the top and bottom legs as shown in the pictures, I only got 2.0 on all three boards. I get the same reading with the red probe on the + of the silver capacitor still yet on 200k setting in ohms- on all three boards, but no other setting on the meter brings up a reading. I dont want to hook up the panel ribbons or power it on until I can do some tests that make sense- any idea where I go from here?
              Attached Files

              Comment

              • tjmethod
                Senior Member
                • Jun 2013
                • 137
                • United States

                #67
                Re: e701i-a3 no picture but backlights

                No reading with black probe on left middle leg and red probe on right lower leg

                Comment

                • freakaftr8
                  Badcaps Legend
                  • Oct 2012
                  • 3743
                  • USA

                  #68
                  Re: e701i-a3 no picture but backlights

                  You should be checking in DC mode on the meter. Ohms won't tell you if you are getting power. Black probe to screw terminal on tcon. Red lead to + side of the capacitor. You can also test voltage at the inductors. 3r3 , 100, and 4R7.

                  Should see 1.0v 3.3v and 15v or so.
                  Last edited by freakaftr8; 10-18-2015, 04:28 PM.
                  Did I leave the soldering iron on?

                  Comment

                  • tjmethod
                    Senior Member
                    • Jun 2013
                    • 137
                    • United States

                    #69
                    Re: e701i-a3 no picture but backlights

                    Originally posted by freakaftr8
                    You should be checking in DC mode on the meter. Ohms won't tell you if you are getting power. Black probe to screw terminal on tcon. Red lead to + side of the capacitor. You can also test voltage at the inductors. 3r3 , 100, and 4R7.

                    Should see 1.0v 3.3v and 15v or so.
                    Not sure you may not have picked up that I have no experience using a volt meter but it seemed the only setting theat I could get a reading was in ohm's on 200k- heres a picture of the exact same multimeter I bought only in black- what should I set the deal on and should I put the red probe in the 10A slot?- also I did put the black probe on the screw and red on the + side of the red cap and also got a reading of 2.0 in 200k on ohm's- somethings obviously wrong if I'm only getting readings on 200k in ohm's. Where would DC be or does this multimeter not have that? I hate to sound like an dumbo but I just haven't used a volt meter much.
                    Attached Files

                    Comment

                    • tjmethod
                      Senior Member
                      • Jun 2013
                      • 137
                      • United States

                      #70
                      Re: e701i-a3 no picture but backlights

                      Silver cap not red

                      Comment

                      • freakaftr8
                        Badcaps Legend
                        • Oct 2012
                        • 3743
                        • USA

                        #71
                        Re: e701i-a3 no picture but backlights

                        Ok. Black probe in COM socket red probe right above it. Not the top socket. That's used for a different application. Have the selector switch set in the top left section in 200 DC mode.

                        Now with tcon connected to the LVDS cable only, run 2 screws into the tv securing the tcon to the tv. Don't worry about the metal cover being there. Now power up tv.

                        Put the black probe into one of the holes that are not occupied by a screw for your ground.

                        Now with the tv powered on, use the red probe and carefully probe those round matte grey canisters on the board. They say 3r3, 100 and 4r4 or something close to that.

                        Are you getting any voltage?
                        Did I leave the soldering iron on?

                        Comment

                        • freakaftr8
                          Badcaps Legend
                          • Oct 2012
                          • 3743
                          • USA

                          #72
                          Re: e701i-a3 no picture but backlights

                          When it comes to trial and error I can't emphasize enough that you must keep your hand on the plug ready to pull the plug if nothing shows up on the screen after you power it up in 3 seconds once you power the TV up you should immediately see the back lights come on along with the silver v in the center of the screen if you do not see this in 3 seconds don't leave it plugged in you will blow up your tcon if there's something wrong still with the panel.
                          Did I leave the soldering iron on?

                          Comment

                          • Tmal0146
                            Member
                            • Oct 2015
                            • 18
                            • Usa

                            #73
                            Re: e701i-a3 no picture but backlights

                            So I got my new tcon board in and plugged up the LVDS cables and powered it up without the bottom ribbon cables plugged in. Tested voltage on the three canisters labeled 3r3, 100, and 4r4. Got 3.3, 12.57, and 0. I'm thinking my "new" board may not be as advertised. I also noticed while I was checking the voltage a small puff of smoke came from somewhere on the board. I also did the ohms test on the transistor and got like 2.45 on the top pin and 10.6 on the bottom pin. Bad board?

                            Comment

                            • Tmal0146
                              Member
                              • Oct 2015
                              • 18
                              • Usa

                              #74
                              Re: e701i-a3 no picture but backlights

                              And tried the new board just to see and got no v on the picture. Tried unplugging each side of the drivers also and still have nothing.

                              Comment

                              • freakaftr8
                                Badcaps Legend
                                • Oct 2012
                                • 3743
                                • USA

                                #75
                                Re: e701i-a3 no picture but backlights

                                Huh. I dont know what to tell you. Did your probe slip off and short something out? I would request an exchange on that board. You should have has read 12v 3.3v and 1.0v IIRC.
                                Last edited by freakaftr8; 10-19-2015, 08:33 PM.
                                Did I leave the soldering iron on?

                                Comment

                                • Tmal0146
                                  Member
                                  • Oct 2015
                                  • 18
                                  • Usa

                                  #76
                                  Re: e701i-a3 no picture but backlights

                                  No. I don't even think I was touching anything when it did that. But the transistor ohmed that way before all that happened. I checked it first.

                                  Comment

                                  • freakaftr8
                                    Badcaps Legend
                                    • Oct 2012
                                    • 3743
                                    • USA

                                    #77
                                    Re: e701i-a3 no picture but backlights

                                    Sounds like you got a bad tcon from the start. I ran into this 3 times on ebay.
                                    Last edited by freakaftr8; 10-19-2015, 08:37 PM.
                                    Did I leave the soldering iron on?

                                    Comment

                                    • Tmal0146
                                      Member
                                      • Oct 2015
                                      • 18
                                      • Usa

                                      #78
                                      Re: e701i-a3 no picture but backlights

                                      It should have ohmed 500 on one pin and some crazy high number on the other though right?

                                      Comment

                                      • Tmal0146
                                        Member
                                        • Oct 2015
                                        • 18
                                        • Usa

                                        #79
                                        Re: e701i-a3 no picture but backlights

                                        I ordered this one from encompass. I'm hoping they will allow me to return it or exchange it for another one that may possibly work.

                                        Comment

                                        • freakaftr8
                                          Badcaps Legend
                                          • Oct 2012
                                          • 3743
                                          • USA

                                          #80
                                          Re: e701i-a3 no picture but backlights

                                          Originally posted by Tmal0146
                                          It should have ohmed 500 on one pin and some crazy high number on the other though right?
                                          Yes
                                          Did I leave the soldering iron on?

                                          Comment

                                          Related Topics

                                          Collapse

                                          • Tynan Dill
                                            Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?
                                            by Tynan Dill
                                            I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.

                                            Upon bringing it home and plugging it up, it showed a standby light.

                                            I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.

                                            The screen seems to blackout and stay black, but with a flashlight I can see the display.

                                            With my Playstation 4 connected via HDMI, and running a game I can hear sound.

                                            Assuming...
                                            11-22-2024, 01:46 PM
                                          • m1ch43lzm
                                            HP Pavilion 15-eh Board DAG7HAMB8F0 - CPU throttling to 0.4GHz (PROCHOT_EXT) and black screen
                                            by m1ch43lzm
                                            Hi, this is my personal laptop, which the original board (lets call it Board A) blew up PU8700 (TPS51486), making a hole on the board, i had left the laptop at my desk one day with the battery fully charged and didn't touch it for a week, but when i tried to turn it on it didn't
                                            Thought the battery was dead, so i plugged in the charger then tried to power on, the power LED blinked once, charged LED still orange, unplugged the charger, plugged in again and I noticed the "magic smoke" smell, so i unplugged the charger, removed the back cover and saw the blown IC (the "magic...
                                            05-12-2025, 08:37 PM
                                          • howardc64
                                            A1312 (27” iMac 2009-2011) A1407 (Thunderbolt Display) A1316 (Cinema Display) Display Black Screen Repair
                                            by howardc64
                                            Problem

                                            This is an LG edge LED lit LCD Display. The LEDs are on the bottom edge of the display. There are 2 bars (left and right) Each bar has many LEDs and a 6 pin connector. Each pin drive several LEDs thus is the highest current flow / heat junction. The weak lead free solder gradually fails with thermal expansion/contraction cycling and increases resistance. PSU will compensate up to a point, then when the current is too high, PSU just shut down the backlight causing a dark display. I have even seen one which the connector just fell off as solder points became completely detached....
                                            08-04-2024, 10:36 PM
                                          • maxim2511
                                            LG 55EC930V OLED - swich on swich of no screen
                                            by maxim2511
                                            My Oled Tv is 55inch tv, 3 days ago I notice that middle of the screen is getting warmer and on picture I have ghosting, missing red color. Color red was still displaying, but it was not so strong as corners of the screen and watching some movies makes me angry.
                                            Then I get an idea to take it apart and clean boards from dust.
                                            In side of Tv was not so bad, I take compressed air in can, and gently blow up.

                                            Also I was thinking to styrofoam sponge to isolate power board from screen that the middle of the screen will not worm so much. Because Led on screen when gets higher...
                                            05-14-2021, 02:21 AM
                                          • Fly_Among_Stars
                                            VIZIO E70-E3 Half picture with half TCON
                                            by Fly_Among_Stars
                                            Hi,
                                            I have a VIZIO E70-E3.
                                            Symptoms: Black screen, no picture, but LED backlights are working.
                                            I probed the power board and voltages are as listed on the board.
                                            Main board appears fine, too.
                                            I believe the problem is either a bad T-CON board, or connection to LCD, or bad LCD.
                                            There are two separate ribbon cables feeding the LCD.
                                            If both are connected, the screen is black.

                                            If only the ribbon cable that feeds the right side of the screen (when viewed from the front) is disconnected, the left side of the screen shows picture and...
                                            04-24-2023, 08:20 PM
                                          • Loading...
                                          • No more items.
                                          Working...