Vizio l42hdtv10a older model help needed

[kiter73]

HI!I was reading all posts about this tv but the board is different than mine.I have same problem no picture,can not power off,no backlight.Power board seems fine .Voltages measure correct.Main board looks good too i mean no burnt stuff or visible problem .Regulators measure fine as far as i could tell by the comments on other posts.I am not too expert in electronic but i might can fix this with help.I have noticed there are 3 different regulators,as far as the AMC1117 regs measure they look good.That is my board on the pic.

[MisterD]

Re: Vizio l42hdtv10a older model help needed

I suggest checking all of the small 3 pin regulators on the Main Board and post part numbers stamped on them, show your voltage readings on each pin, measure DC Voltage and ground negative/black volt meter lead to chassis.

[kiter73]

Re: Vizio l42hdtv10a older model help needed

i have found one is not right,U5 adj. voltage lil higher than it suppose to be !i go ahead figure out ,digikey sell them if i am right.i do not have any idea what part number or ho to find it.

[budm]

Re: Vizio l42hdtv10a older model help needed

1117 series LDO from DIGIKEY:

Adjustable:
http://www.digikey.com/product-detai...SCT-ND/1967218

1.5V fixed:
http://www.digikey.com/product-detai...SCT-ND/2121241

1.8V fixed:
http://www.digikey.com/product-detai...SCT-ND/1967216

2.5V fixed:
http://www.digikey.com/product-detai...SCT-ND/2121243

3.3V fixed:
http://www.digikey.com/product-detai...OSCT-ND/660708

This is the way to figure out if the adjustable regulator is good or not:
Notes: we are looking at the regulator with the Big tab up (the big tab is tied internally to the center pin).
Adjustable regulator will have two resistors attached to it, one resistor (Rfb) is between pin1 and pin2, another resistor (Rg) is between pin1 and ground. Pin3 is an input pin.
The voltage between the Adjust pin (left pin) and the center pin (Pin2, output) will always be 1.25V +/- 2% (this is the precision voltage reference), if it is not, it is bad.
To figure out what the output voltage should be: measure the voltage between pin 1 and ground and add 1.25V to that number, that is the output voltage on pin 2 but you have to make sure you do have 1.25 between pin 1 and 2 as noted above.
See my Voltage calculator spreadsheet here, post #6:
https://www.badcaps.net/forum/showth...417#post273417

[kiter73]

Re: Vizio l42hdtv10a older model help needed

Thanks!I ordered will see what's gonna happen

[kiter73]

Re: Vizio l42hdtv10a older model help needed

Just soldered in !TV still laying on the floor but turned on and have sound and backlight Should work fine .Thanks for the part number !!!!And for the help!!I keep 2 more regulator for future problem.

[budm]

Re: Vizio l42hdtv10a older model help needed

Great, thanks for the feedback.