My name is John,
It sound like you have a defective power supply, I have worked on a ton of them and the power supply is a simple switch mode supply that uses a few fets to take the Line voltage of 120 volts @ 60hz AC to a few different DC voltage supplies like 24vdc, 12v, 5v, 3.3v and 15v all DC which is what most electronics run on.
To check for obivious failure,
First remove the back cover, which means laying the set on its face on the floor and removing the stand as on this unit the stand block the cover from being removed. To lay it safely you will need a large area and make sure it is very clean and VERY LEVEL as because this is a LCD even the slightest pressure on the screen itself can cause the LCD to crack so make sure the pressure is only on the front cover around the LCD itself.
You will see a board that the power plug connects to this is called the small power supply. This is your most likely failure look at the board and you should see some cylinders with a silver top they should all be flat if they some are not the board is most likely repairable. The parts will cost you about 20 bucks (when you include shipping and the a servicecenter extra fee most places rob you with) If you do not see any of these swollen caps (the silver tops) then the power supply most be replaced they can be expensive ranging between $100-$250 for the part. First i would open and see if you can save a buck and repair it by replacing the damaged caps. If you dont feel comfortable with replacing the caps this could easily be repaired by a local repair shop for under $150.00 (if they are reputable)
Swollen caps might look something like this:
If you wish to attempt this repair yourself:
read the numbers down the side of the capacitors they should have a white stripe (neg side always install them the same direction) and then they should be marked like this 1000mfd 50v or the "1000mfd" is the micro farad rating this is a contant do not install anything but the same mfd rating but the "50v" is the maxium voltage rating and this you can increase to anything that will fit 65v 100v 200v or larger but never smaller. The bigger the voltage the bigger the size of the cap.
You can order the parts from http://www.digikey.com/ expect to pay around $20.00 for the parts but you will need a good pencil soldering iron, solder and desoldering braid. If you dont have the tools and materials the cost of the equipment will be more then the cost of having it professionally repaired and when you do it if you make a mistake your ordering a $300 power supply, and it doesnt carry a warranty. If you have the tools it is simple enough if you dont you can order them from www.mcminone.comit has to be adjustable and at least 40w 21-3475 - WLC100 Solder Station is the cheapest one i could find that would suit your needs20-2788 - Solder-Wick Rosin - .110'' x 25' copper wick, this is the only stuff i use there is some really cheap stuff out there and it is horrible to work with in supplies.21-1840 - 44 Rosin Core Solder - 60/40 - 1 lb. x .031'' - 21 Gauge this is the solder you will need.
Hope this helps,If you do want to get it professional serviced i would recommend looking at www.citysearch.com or www.tvrepairpros.com Thanks again,John
IF YOU HAVE ANY QUESTIONS PLEASE ASK
I will inspect the powersupply as you described. This may take a while, because I am alone and I need help lifting the TV off the wall. Customer/p>
I am not sure what you mean?
let me know,
Not really all that complicated it is plug and play, just unscrew the 4-6 screws and unplug the few wires and reverse the process, very simple.
If you give me the model number i can supply you with the part number.
Model# XXXXX L37 HDTV
Part # XXXXX /p>
0500-0507-0190 - power supply, you could also order this part from encompassparts.com but i recommend www.partstore.com they have a better return policy.
Okay please remember to accept as this site only pays experts based on the accepts, please understand i am not saying this will for sure fix the set just that you are asking for my skilled opinion for what i think may be wrong, since i can not see touch or test the product all i can give you is advise on what i believe to be causing the problem. That is what the site is intented to provide you with, since you pay only a small fee instead of a diagnostic fee that many shop charge at least $40 to perform a diagnostic this site try to allow you to seek professional advice from real experts.
I hope you can accept and i appricate you allowing me to provide you an answer.
Possibly the main board but vizio does not have a really history of that however it is the most common cause of no power on sharp sets, as the 5 volt supply is damaged on the board preventing the micro from properly working, not common but it can be the cause.
If the power supply does not resolve the issue return it and order the main board P# 3370-0052-0150 it is quite a bit more expensive than the supply and since it is a rare failure i doubt you will have this problem but just to be safe here is the number.
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I hate to say it but have you tried not telling them it was installed, they have no way to prove any install or not.
However it really should have resolved the issue of a power problem but since it did not it means it data lines are down which is rare but you will need to replace the main board. I hate when that happens but without a scope and a schematic i would have to do the same thing just replace the power supply.
They have to accept the part back you just have to fight them a little and order the main board Part # 3370-0052-0150
Wish it was more of an exact science but 95% of the time no power on this model is the power supply but in this case it would have to be the main board.