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Vizeo E500i AO dead with led on

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    #21
    Re: Vizeo E500i AO dead with led on

    And HOT SIDE is DEADLY, so do not touch anything on the HOT side with your hands or body, best to plug the TV into GFCI outlet to get some protection.
    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

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      #22
      Re: Vizeo E500i AO dead with led on

      C120 = 170v to 298v
      jp113 =14v
      jp116 = 16v to 20v then back to 16v

      I hope you didn't want me to do the pin read the outputs on the 2 ic120 & 150 --- my eye's are not as good as they used to be and a little dark in the garage.

      Maybe we should try fixing the on/off led problem so that I can get the same reading every time. It might fix the varied readings that I keep getting?

      Can I just permanently jumper with a 1kresistr 201 -pin 8 to pin 1? and would that stabilize the readings? for further testing?

      Comment


        #23
        Re: Vizeo E500i AO dead with led on

        Yes you can use a 1k resistor between 5.2vsb and Remote on/off but you need to disconnect the cable going to the main board so you don't damage the main board.
        It could be that the voltage on jp116 is low/changing because C602 or C606 are weak. These are supplied by the standby circuit and should be steady.
        If the voltage on C120 increases when powered on, then ic120 (pfc) is working so no need to check it. but the voltage does seem about 100 volts low, This could be because of a shorted diode around L120, like D121B or the other two I can't make out the numbers.
        Also post the numbers on ic120 & ic150. It could be that ic150 (the main drive ic) is not turning on due to a low pfc voltage. ic150 does seem to monitor the pfc voltage via R161a~c
        Last edited by R_J; 05-26-2020, 09:16 PM.

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          #24
          Re: Vizeo E500i AO dead with led on

          D121a and b test ok
          c602 read 21.57mf = ok
          c606 reads 22mf = ok

          c120 v still low

          And yes, using c120 neg./gnd

          Have not done reading on ic's

          Comment


            #25
            Re: Vizeo E500i AO dead with led on

            What about the other diode? it might be D120? I don't have a schematic so without the ic numbers I don't know what else to check.
            If you can't make out the ic numbers you might need to clean them with alcohol and maybe look at an angle to read it.
            Last edited by R_J; 05-27-2020, 08:17 PM.

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              #26
              Re: Vizeo E500i AO dead with led on

              What I found R_J :

              Also resistance tested OK on D120.
              all 3 diodes read 171 vdc on each cathodes -
              Will try checking the voltages on each one to be sure they are working - What is the voltage coming out of D120, D121A & B?
              Thanks for your help patience R_J. If nothing else I do appreciate your encouragement.
              C120 = 171 on and off.
              Decided to test the ac across c120 -340 ac off and 668 ac on. Removed c120 to retest with a few other meters, besides one of my ESRs. C120 =140.2uf ---should be 150. Seems close enough.
              Why does the AC voltage double and the DC doesn’t at that cap? I must be missing something???

              Comment


                #27
                Re: Vizeo E500i AO dead with led on

                What ac voltage are you talking about that is doubling? The ac from the line is rectified to 160VDC, Then when the power supply is turnd on, the PFC circuit starts and using high frequency switching, boosts the 160v to about 385vdc. on C120
                What is the make and model of the meter you are using? It is very possible that C120 is bad.
                Last edited by R_J; 05-29-2020, 10:43 AM.

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                  #28
                  Re: Vizeo E500i AO dead with led on

                  You tested esr already, not sure what kind of meters you have, a simple test for caps specially out of circuit is: To test the capacitor with a multimeter, set the meter to read in the high ohms range, somewhere above 10k and 1m ohms. Touch the meter leads to the corresponding leads on the capacitor, red to positive and black to negative. The meter should start at zero and then moving slowly toward infinity, easy peasy.
                  Last edited by nomoresonys; 05-29-2020, 12:03 PM.

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                    #29
                    Re: Vizeo E500i AO dead with led on

                    Where is the AC coming from? Either a step up xformer or an ac voltage doubler is causing the AC voltages - and the diodes aren't doing their job??? And why is this AC cross the c120 cap?
                    very odd indeed.
                    A schematic of that particular circuit area would be very helpful.
                    R_J any idea as to where and how this new AC voltage has appeared? It's got me...

                    Comment


                      #30
                      Re: Vizeo E500i AO dead with led on

                      I think you have resolved the mystery R_J - It was a cheap cen-tech meters from Harbor Freight - I was using two of them from Cen-Tech out in the garage and they both read 340 to 670. Even the HV led came on - That is the first time I ever found such a defect in the meters from HF... Will tell them about it on my next visit - Though they may not care -
                      I have decided that I am going to use my other brand meters , like my flukes, etc. I will also tell all I meet about the $5 meters.
                      Sorry but I am going to go through all my previous reading again - so it may take a few days to get back to you all. But I think it would be best - to be sure of all readings. So please give me a few days to get this done. And Thanks mucho on the check the meter R_J. - I never even thought about it being bad because I usually would only test resistors, fuses and simple circuit testing.
                      I actually was talking to a friend who wants get a meter and I told him that same defective meter was good enough - but will have to call him up and tell him to forget that meter. lol

                      Nomoresonys - Thanks for the info but I do know how to check caps - I prefer the ERS which I use the most often - I have Simpson's, Heathkits, etc. My last job working for others was as a senior tech for Heathkit for years until they were bought out by Zenith - Then I started my own business. That was about 35 yrs ago. But I am in my 80's and so getting lazy and more ragged with it all. LOL

                      Comment


                        #31
                        Re: Vizeo E500i AO dead with led on

                        Well you're doing just fine, at my present rate if/when I get to 80's I doubt if I'll even know my own name.
                        Last edited by nomoresonys; 05-29-2020, 01:56 PM.

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                          #32
                          Re: Vizeo E500i AO dead with led on

                          LOL - That happens to me all the time - nomoresonys. But it is really nice that you guys are there to help us crazies -
                          I am scratching my head, thinking what am I doing trying to fix a friends tv when they have enough money to by 10 new ones???

                          Comment


                            #33
                            Re: Vizeo E500i AO dead with led on

                            If it was an easy fix, wouldn't be a problem but if the damn thing has you pulling your hair out, like a lot of troubleshooting does, I would damn sure charge m for the aggravation specially if they got spare bucks.

                            Comment


                              #34
                              Re: Vizeo E500i AO dead with led on

                              OK, I am starting new---
                              I tried measuring ic120 and ic 150 -but I am having trouble with them. When I try to turn on the power led it only stays on for about 5 sec. and so by the time I get to the ic they are off - no power on pin 14, or what ever pins are the power. I really need to correct the intermittent power on/off problem - It has been the real pain in the neck besides using the defective vom.
                              I can not get any readings until I have consistent power. need the white led light to remain on - I really think that I am wasting you guy's time, with such false readings.
                              I we can fix the on/off problem - then I can get solid readings.
                              I hope this is a help.
                              If you guys find this too much of a pain in the neck - I would understand and thank you for the effort.

                              Comment


                                #35
                                Re: Vizeo E500i AO dead with led on

                                I tried to get the part numbers off of ic 120 & ic120 - I couldn't read them - My plan was to look up their data sheet to try checking out their inputs and outputs, but the print of the their info was unreadable, even with magnifying glasses.

                                Comment


                                  #36
                                  Re: Vizeo E500i AO dead with led on

                                  perhaps start over again.... provide a picture of the back with everything connected so the forum can see what you are up against. I know you have done a "bunch", but have you checked the backlights? Perhaps the "shutdown" is because of a back light issue and not so much a power supply issue which you seemed to have started at with some "questionable meter". Outside of the standby voltage, it is quite likely that others that are labelled for the connectors on the power board may not stay around very long so you need to be monitoring them (one at a time) during power button pushes with a reasonable meter that can potentially see any temporary voltage condition. Further, when you press the power button, you need to monitor the ps-on pin to see if it changes. Repeat looking at the other labeled pins on connector cn9101. Go from the results that you would post. That will give the forum a better idea of what the state of the board is.

                                  oops I pulled up a picture of the wrong board ... sorry.
                                  Last edited by budwich; 06-01-2020, 12:11 PM.

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                                    #37
                                    Re: Vizeo E500i AO dead with led on

                                    sorry about the previous post...
                                    but still reading thru the thread, I am wondering about the checks for the voltages. You indicate no 12v, are there but are you looking / monitoring it during the attempted start up or a bit "after the fact". It could be up and down relatively fast and be there when you get around to measuring for it. In the same flavor of my previous post, what is happening with pin 9 during power up / blacklights initially flashing? Also, when you did your "jumper test", did you check the voltages going out to the backlights on cn301 (careful of the high voltage).

                                    As for my previous post, it would still be good to get a picture of the back to see how things are connected.
                                    Last edited by budwich; 06-01-2020, 12:36 PM.

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                                      #38
                                      Re: Vizeo E500i AO dead with led on

                                      LOL, Budwich, about wrong board.
                                      Yes, I have checked the 12v with power on and off - I could do that with out any trouble. No 12 v at all.
                                      I just went out and rechecked pin 9 of cn201, get no change when led is on or off. I put my fluke 77 on hold and no real change on pin 9.
                                      Do you want me to take a picture on the back of the PS board ?
                                      Well if so here it is.
                                      Thanks for the help.
                                      Attached Files
                                      Last edited by rayxoxo; 06-03-2020, 08:18 PM.

                                      Comment


                                        #39
                                        Re: Vizeo E500i AO dead with led on

                                        OK... thanks.... sorry for the "side track".

                                        back to the "regular program".... a way back, you indicated a problem with trying to measure thigs at an IC but could not because of the time to take the measurement versus how fast it powered down was too short. OK... but it was indicated that you can force on the power supply via a "resistor jumpered" between pins. Have you retried that method again with your "new meter"? The jumpering will allow the ps to stay on for as long as the jumper is in place and let you do as many checks as you want.

                                        similarly along the lines of the jumper test, during one of those types of "power up", can you disconnect the led connector (cn301) to see if anyrhing changes with the 12v during power up there after.
                                        Last edited by budwich; 06-04-2020, 05:03 AM.

                                        Comment


                                          #40
                                          Re: Vizeo E500i AO dead with led on

                                          Now that you have a different meter, check the DC voltage across C120 in standby, then force the power on with the 1k resistor to see if the voltage increases. This test will tell you if the pfc circuit is working or not.

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