If the tv is cold and has been unplugged for several days it will power up fine, but after a short time goes down to backlights only. The VIZIO front light stays bright. The power board and the regulator on the main board test good. I took a can of dust spray and I knew if it was upside down it would putout cold propane gas. I tried cooling down some components. In the picture see the heat sink on the far left side of the board cover with metal with holes in it. I marked it with a yellow arrow. When I cooled that part down the set came right on. Does anyone know what the function of that component is and what I might do to correct the problem? Re-solder perhaps? I have not found an drawing of that board so it is hard to know where to go from here. The board number is CBPF9D1KZ4. BTY this forum is fantastic!
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VIZIO VT420M Power up issue
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Re: VIZIO VT420M Power up issue
You will have to remove that shield to see what are in side that section.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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Re: VIZIO VT420M Power up issue
Okay I decided to take the metal cover off and heated the heat sink to melt the glue holding it on. So this is the processor in fact it says AMD on it so it must be. From the top I don't see any soldered connections. I see connections on the underside of the board. How should I go about reflowing the connections?
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Re: VIZIO VT420M Power up issue
I tried reflow on the back of the board or the underside of the suspect chip. It did not work. Looking at the top of the chip where the part number are there are no visible soldered connections. That's why I heated the other side for reflow. It was when I super cooled the heatsink that tv set came on normally. Cloud it be the chip that is bad?
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Re: VIZIO VT420M Power up issue
I found a process for DIY reflowing here on the forum. Remanufactured main boards for this are $125 plus shipping and no one has replacements in stock. Ebay has none either. $125 is more than the set is worth, so I'll give this a shot. When I heated the underside I only I think it got just hot enough to make it worse. This process will evenly heat top and bottom to a predetermined temp.
https://www.badcaps.net/forum/showthread.php?t=36740
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Re: VIZIO VT420M Power up issue
That is a lot of money for main board for 42" 2010 TV.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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