Help- Vizio VW42L HDTV10A

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Re: Help- Vizio VW42L HDTV10A

yes it is a K1117S15. I am learning here Thank you for your patience. So this means U9 is bad?

[retiredcaps]

Re: Help- Vizio VW42L HDTV10A

My bad! you are are correct my friend. It is a K1117.

Precision matters here. It is K1117S15. The S15 matters because it tells us the correct output voltage (1.5V). K1117 by itself suggests an adjustable regulator. So if pin 1 is 0 and pin 2 is 1.50, that means it is a bad regulator.

[XmouseX]

Re: Help- Vizio VW42L HDTV10A

My bad! you are are correct my friend. It is a K1117.

[retiredcaps]

Re: Help- Vizio VW42L HDTV10A

By the way, on page 9-5 on the service manual, it suggests that U2 should be 3.3V output.

So pin 1 should be roughly 2.05V. Pin 1 + 1.25 = 3.30 for pin 2. So it is possible that the components feeding pin 1 are low or U2 itself is bad.

[retiredcaps]

Re: Help- Vizio VW42L HDTV10A

To hedge my bets, the caps around U2 could be bad as well. Namely CE5, CE6, and others in that area. See post #38 below.

[retiredcaps]

Re: Help- Vizio VW42L HDTV10A

Yes those are the part numbers.

Not according to the pictures (which is why we ask for them - selldoor can back me up on this one).

U9 on the main board is K1117S15. U9 on the t-con is RT9164A.

U2 is bad. 52 cents at digikey.com

http://www.digikey.com/product-detai...ICT-ND/1301524

[XmouseX]

Re: Help- Vizio VW42L HDTV10A

Yes those are the part numbers. The U9 that I mentioned earlier is on the TCON board. This U9 is on the main control board in the second set of pictures. It is confusing that there is 2 U9's.

[retiredcaps]

Re: Help- Vizio VW42L HDTV10A

U9
AMC1117
pin1 - 0V
pin2 - 1.51V
pin3 - 3.3V


U2
AMC1117
pin1 - 1.45V
pin2 - 2.30V
pin3 - 5.10V

1) Are you sure about the part numbers for U9 and U2? In the picture, it looks like U9 is K1117S15? The 15 at the end indicates it is a fixed regulator outputting 1.5V which would make U9 a good regulator.

Please re-check all your part numbers and make sure it is not a cut&paste error.

2) U2 is an adjustable voltage regulator and it is bad. Pin 2 should be pin 1 + 1.25V or 1.45 + 1.25 = 2.70V. At 2.30, it is way too low.

[XmouseX]

Re: Help- Vizio VW42L HDTV10A

U33
AMC1117
pin1 - 2V
pin2 - 3.3V
pin3 - 5V

U7
AMC1117
pin1 - 0V
pin2 - 1.28V
pin3 - 3.3V

U9
AMC1117
pin1 - 0V
pin2 - 1.51V
pin3 - 3.3V

U8
AMC1117
pin1 - 2.05V
pin2 - 3.3V
pin3 - 5.15V

U2
AMC1117
pin1 - 1.45V
pin2 - 2.30V
pin3 - 5.10V

hope this helps

[XmouseX]

Re: Help- Vizio VW42L HDTV10A

Ok so real quick I am still testing regulators, but the Voltage reading for the LVDS cable pinouts were...pin1=0V, Pin2=0V, pin3=2.4V and pin4=3.3V

[retiredcaps]

Re: Help- Vizio VW42L HDTV10A

Another suggestion. Please retest all the voltage regulators on the main board and list the pcb designation, part number, and readings for each pin like so

U33
AL1117-33
pin 1 = 0.0
pin 2 = 3.3
pin 3 = 5.0

Maybe we can spot something you missed?

[XmouseX]

Re: Help- Vizio VW42L HDTV10A

Dont know if this matters, bu I just jumped 5V to pin 13 on J1 and the backlight came on....I will do the tests that you suggested. Thank you

[retiredcaps]

Re: Help- Vizio VW42L HDTV10A

I have more suggestion. Disconnect the LVDS cable from the main board. Now measure the DC voltage of LVDS pins 1, 2, 3, and 4 on the main board with respect to ground. Do you get voltage on any of them?

[retiredcaps]

Re: Help- Vizio VW42L HDTV10A

Focus on page 9-5. Test everything on that page inside the rectangular box. Report your findings for each box.

[XmouseX]

Re: Help- Vizio VW42L HDTV10A

Thank you so much for your time I do have the manual already. I am just not sure how the flow chart works when it says how is the inverter?...Um it doesn't work..lol. But it doesnt give you a next step after that. Well thank you for all the help anyway.

[retiredcaps]

Re: Help- Vizio VW42L HDTV10A

Service manual is at



It does have a troubleshooting section. Maybe verify you did all the steps?

[retiredcaps]

Re: Help- Vizio VW42L HDTV10A

Did you see post #23?

[XmouseX]

Re: Help- Vizio VW42L HDTV10A

Yes sir U33 was 3.3V exactly , U7 was 1.27V and U9 was 1.53V. Also I checked F1 and F2. Both were 00.2 ohms and seemed fine.

[retiredcaps]

Re: Help- Vizio VW42L HDTV10A

3) What is part number U32 on the main board?

4) I forgot to award you one retiredcaps' bonus point for a picture of your Greenlee multimeter. I can't quite make out the model number, but I know I have seen pictures of it before.

[retiredcaps]

Re: Help- Vizio VW42L HDTV10A

1) On the main board, are fuses F1 and F2 good?

2) You mentioned that all the voltage regulators tested good in post #1. I'm assuming you meant all the voltage regulators on the main board like the infamous U33 and U7?