Folks, I could use some info.
A Google search on this model of VIZIO TV yields many LED and LED power supply issues. Also, YouTube provides many good LED tv repair videos. ShopJimmy.com even has a video on this very model and how to trouble shoot the "sound but no-backlight" problem. Been there, done that. My unit has sound, a dark screen, and passes the flashlight test - there is full video on the in-lit screen. I just don't have BACK LIGHTS. What none of the excellent troubleshooting sources provide are the answer to a couple of simple questions:
1. How can I test the LED strips of this unit without the slick ShopJimmy.com LED tester, which is not available? What voltage is needed to light the individual LED strips to determine if any are bad? I don't have an E lab at my disposal so it needs to be a simple solution. Telling me to use a "wallwort" won't get it as I don't know what one is in the USA ;-)
2. Is there a VOM (or other) method of testing the LED strips? If so, what should the readings be at the main plug, or on each strip?
3. Others have posted that they have 66v at +Vout 1 and +Vout 2 pins of the Power/Driver board with the LED supply plug connected or disconnected (as do I). What's the cause? What components are most likely the culprits? I can't locate a schematic or functional diagram of this board anywhere. (Did I just show my age? After all, I am an old discrete component era tech;-) )
I ordered a new PS board and when installed, it had the same issues as the one I removed - 66V vs ~87v on v1out and ~128v on v2out from the output of the LED driver section. The supplier is going to replace it but I'm concerned I could get another bad one or my LEDs might be blowing the good board's output section. (I intend to leave the LED cable disconnected and measure the output of the next board FIRST).
Am I over-thinking this problem? Any knowledgeable response would be appreciated. Most strings on these issues just die with no posted resolution.
Regards,
/herb
A Google search on this model of VIZIO TV yields many LED and LED power supply issues. Also, YouTube provides many good LED tv repair videos. ShopJimmy.com even has a video on this very model and how to trouble shoot the "sound but no-backlight" problem. Been there, done that. My unit has sound, a dark screen, and passes the flashlight test - there is full video on the in-lit screen. I just don't have BACK LIGHTS. What none of the excellent troubleshooting sources provide are the answer to a couple of simple questions:
1. How can I test the LED strips of this unit without the slick ShopJimmy.com LED tester, which is not available? What voltage is needed to light the individual LED strips to determine if any are bad? I don't have an E lab at my disposal so it needs to be a simple solution. Telling me to use a "wallwort" won't get it as I don't know what one is in the USA ;-)
2. Is there a VOM (or other) method of testing the LED strips? If so, what should the readings be at the main plug, or on each strip?
3. Others have posted that they have 66v at +Vout 1 and +Vout 2 pins of the Power/Driver board with the LED supply plug connected or disconnected (as do I). What's the cause? What components are most likely the culprits? I can't locate a schematic or functional diagram of this board anywhere. (Did I just show my age? After all, I am an old discrete component era tech;-) )
I ordered a new PS board and when installed, it had the same issues as the one I removed - 66V vs ~87v on v1out and ~128v on v2out from the output of the LED driver section. The supplier is going to replace it but I'm concerned I could get another bad one or my LEDs might be blowing the good board's output section. (I intend to leave the LED cable disconnected and measure the output of the next board FIRST).
Am I over-thinking this problem? Any knowledgeable response would be appreciated. Most strings on these issues just die with no posted resolution.
Regards,
/herb
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