Hi everyone,
I just picked up a broken Vizio VXT3D474SV from a friend. Reportedly, they had a technician come out and replace 1 or more of the circuit boards but the TV still did not work and it was declared dead. On bringing it home, I cleaned it up and powered it on. Amazingly, it worked absolutely fine for about 20 minutes. Then, as I was flipping through channels, the screen became garbled. I tried to reboot the TV but it does not want to power back on.
Symptoms:
* After plugging in power, TV goes through normal boot sequence (LED logo blinks amber/white for a few minutes), then settles into standby mode (amber LED)
* After turning on the TV with power button or remote, the LED turns white but nothing else happens. No sound, and no image (I checked using a flashlight). On rare occasions, the backlight will turn on, but usually it doesn't.
* After a few minutes, the TV reboots (flashing amber/white LED)
Diagnostics:
* All capacitors look undamaged.
* I have checked all the voltages coming out of the power supply and they are all good.
* I checked voltage drop and continuity across all the fuses (one large fuse on PSU and several ceramic fuses on other boards) and they are all good.
* I was only able to find one voltage regulator (a 7805 on the motherboard) and its output is nominal.
Here are a couple threads that describe the same issue:
https://www.badcaps.net/forum/showthread.php?t=38370
https://www.badcaps.net/forum/showthread.php?t=23735
https://www.badcaps.net/forum/showth...3D424SV&page=2
http://www.tv-forums.com/cgi-bin/gfo...9172837#154479
http://www.tv-forums.com/cgi-bin/gfo...9172837#152379
Pictures:
http://imgur.com/a/IrgLf
Based on all of this, I believe the problem is with the t-con board, but every place I have looked online is sold out of replacements (probably because this is a common issue with this TV). Thus, I would like to try and fix the board I have.
Since the TV did work momentarily, I think we can make some deductions. The faulty component must be one that became functional again after either sitting idle for a long time (weeks or months), or getting shaken during the car ride home. This component then failed after warming up (operating for about 20 minutes). Do you guys think this could be a capacitor issue? They all look fine but I know that doesn't necessarily mean they don't have problems.
I just picked up a broken Vizio VXT3D474SV from a friend. Reportedly, they had a technician come out and replace 1 or more of the circuit boards but the TV still did not work and it was declared dead. On bringing it home, I cleaned it up and powered it on. Amazingly, it worked absolutely fine for about 20 minutes. Then, as I was flipping through channels, the screen became garbled. I tried to reboot the TV but it does not want to power back on.
Symptoms:
* After plugging in power, TV goes through normal boot sequence (LED logo blinks amber/white for a few minutes), then settles into standby mode (amber LED)
* After turning on the TV with power button or remote, the LED turns white but nothing else happens. No sound, and no image (I checked using a flashlight). On rare occasions, the backlight will turn on, but usually it doesn't.
* After a few minutes, the TV reboots (flashing amber/white LED)
Diagnostics:
* All capacitors look undamaged.
* I have checked all the voltages coming out of the power supply and they are all good.
* I checked voltage drop and continuity across all the fuses (one large fuse on PSU and several ceramic fuses on other boards) and they are all good.
* I was only able to find one voltage regulator (a 7805 on the motherboard) and its output is nominal.
Here are a couple threads that describe the same issue:
https://www.badcaps.net/forum/showthread.php?t=38370
https://www.badcaps.net/forum/showthread.php?t=23735
https://www.badcaps.net/forum/showth...3D424SV&page=2
http://www.tv-forums.com/cgi-bin/gfo...9172837#154479
http://www.tv-forums.com/cgi-bin/gfo...9172837#152379
Pictures:
http://imgur.com/a/IrgLf
Based on all of this, I believe the problem is with the t-con board, but every place I have looked online is sold out of replacements (probably because this is a common issue with this TV). Thus, I would like to try and fix the board I have.
Since the TV did work momentarily, I think we can make some deductions. The faulty component must be one that became functional again after either sitting idle for a long time (weeks or months), or getting shaken during the car ride home. This component then failed after warming up (operating for about 20 minutes). Do you guys think this could be a capacitor issue? They all look fine but I know that doesn't necessarily mean they don't have problems.
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