Vizio GV47LFHDTV10A No Picture No Sound Fix

[budm]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

Are you referring to pin 1 on the main board that gives the signal to BL-ON on the power supply board?

I am talking about checking the LDO Voltage regulator ICs 3-pin device.

[bleed4me]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

First I just want to say hats off to budm for his thread /tutorial for Voltage Regulator (LDO) testing, thats good reading right there so thank you for that. So I tested the voltages then checked then rechecked just to make sure. As far as the part number I did the best I could that wasnt an easy task. There were some that had a backwards C so I will use " ) " in its place. If there are any you want me to recheck please let me know and I will get right on it. Also if the format is incorrect please let me know. Thanks

U4
)117BB
17-33L
PIN 1=0
PIN 2=4.06
PIN 3=6.30

U5
AMC1117
F0720F
PIN 1=.56
PIN 2=1.56
PIN 3=4.02

U6
)117BB
17-33L
PIN 1=0
PIN 2=3.76
PIN 3=5.85

U8
)117BB
17-33L
PIN 1=0
PIN 2=4.07
PIN 3=6.24

U9
AMC1117
18F0641J
PIN1= 0
PIN 2= 2.16
PIN 3= 3.98

U10
AMC1117
18F0641J
PIN 1= 0
PIN 2= 2.18
PIN 3=4.01

U7
AMC1117
18F0641J
PIN 1= 0
PIN 2=2.15
PIN 3= 3.96

U18
AMC1117
F0720F
PIN 1= .29
PIN 2= 1.78
PIN 3= 3.92

DU2
)117BB
17-33L
PIN 1=0
PIN 2= 3.88
PIN3=5.96

DU3
)116LC
17-25L
PIN 1=0
PIN 2=2.9
PIN 3=5.86

DU4
AMC1117
F0720F
PIN 1= 0
PIN 2=.78
PIN 3= 3.83

U16
)116LC
17-25L
PIN 1=0
PIN 2=2.88
PIN 3=5.82

[budm]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

There are many readings. you need to check your meter first and make sure the batteries are good and the setting is set to DCV.

U4 Bad, it is 3.3V regulator, you are getting 4.06V
)117BB
17-33L
PIN 1=0
PIN 2=4.06
PIN 3=6.30

U5 Bad, 1.25V ref +0.56 = 1.81
AMC1117
F0720F
PIN 1=.56
PIN 2=1.56
PIN 3=4.02

U6 Bad, it is 3.3V regulator
)117BB
17-33L
PIN 1=0
PIN 2=3.76
PIN 3=5.85

U8 Bad, it is 3.3V regulator
)117BB
17-33L
PIN 1=0
PIN 2=4.07
PIN 3=6.24

U9 Odd output Voltage
AMC1117
18F0641J
PIN1= 0
PIN 2= 2.16
PIN 3= 3.98

U10, Odd output Voltage
AMC1117
18F0641J
PIN 1= 0
PIN 2= 2.18
PIN 3=4.01

U7
AMC1117
18F0641J
PIN 1= 0
PIN 2=2.15
PIN 3= 3.96

U18 Bad, 1.25V ref + 0.29 = 1.54
AMC1117
F0720F
PIN 1= .29
PIN 2= 1.78
PIN 3= 3.92

DU2 Bad, it is 3.3V reg.
)117BB
17-33L
PIN 1=0
PIN 2= 3.88
PIN3=5.96

DU3 Bad, it is 3.3V reg.
)116LC
17-25L
PIN 1=0
PIN 2=2.9
PIN 3=5.86

DU4
AMC1117
F0720F
PIN 1= 0
PIN 2=.78
PIN 3= 3.83

U16
)116LC
17-25L
PIN 1=0
PIN 2=2.88
PIN 3=5.82

[Gaines]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

Great thread!

[bleed4me]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

Ok just replaced the battery with a brand new one and did some retesting... Just redid all the values, sorry about this... what a difference a new battery makes! Thank you for the suggestion



U4
)117BB
17-33L
PIN 1=0
PIN 2=3.35
PIN 3=5.21

U5
AMC1117
F0720F
PIN 1=.46
PIN 2=1.29
PIN 3=3.35

U6
)117BB
17-33L
PIN 1=0
PIN 2=3.33
PIN 3=5.21

U8
)117BB
17-33L
PIN 1=0
PIN 2=3.35
PIN 3=5.15

U9
AMC1117
18F0641J
PIN1= 0
PIN 2= 1.81
PIN 3= 3.35

U10
AMC1117
18F0641J
PIN 1= 0
PIN 2= 1.81
PIN 3=3.35

U7
AMC1117
18F0641J
PIN 1= 0
PIN 2=1.81
PIN 3= 3.35

U18
AMC1117
F0720F
PIN 1= .25
PIN 2= 1.51
PIN 3= 3.35

DU2
)117BB
17-33L
PIN 1=0
PIN 2= 3.32
PIN3=5.12

DU3
)116LC
17-25L
PIN 1=0
PIN 2=2.52
PIN 3=5.12

DU4
AMC1117
F0720F
PIN 1= 0
PIN 2=.66
PIN 3= 3.32

U16
)116LC
17-25L
PIN 1=0
PIN 2=2.52
PIN 3=5.14

[budm]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

U4 OK, 3.3V REG
)117bb
17-33l
pin 1=0
pin 2=3.35
pin 3=5.21

u5 Bad, 1.25v ref + 0.46adj = 1.71V, you have 1.29V Out.
amc1117
f0720f
pin 1=.46
pin 2=1.29
pin 3=3.35

u6: OK, 3.3V REG
)117bb
17-33l
pin 1=0
pin 2=3.33
pin 3=5.21

u8: OK, 3.3V Vreg
)117bb
17-33l
pin 1=0
pin 2=3.35
pin 3=5.15

u9:OK, 1.8V Vreg
amc1117
18f0641j
pin1= 0
pin 2= 1.81
pin 3= 3.35

u10: OK, 1.8V Vreg
amc1117
18f0641j
pin 1= 0
pin 2= 1.81
pin 3=3.35

u7: OK, 1.8V Vreg
amc1117
18f0641j
pin 1= 0
pin 2=1.81
pin 3= 3.35

u18: OK, 1.25Vref + 0.25Vadj = 1.50Vout
amc1117
f0720f
pin 1= .25
pin 2= 1.51
pin 3= 3.35

du2: OK, 3.3V Vreg
)117bb
17-33l
pin 1=0
pin 2= 3.32
pin3=5.12

du3: OK, 2.5V Vreg
)116lc
17-25l
pin 1=0
pin 2=2.52
pin 3=5.12

du4 Bad. This one needs verification on the P/N. Output cannot be lower than Vref which is 1.25V.
amc1117
f0720f
pin 1= 0
pin 2=.66
pin 3= 3.32

u16: OK, 2.5V Vreg
)116lc
17-25l
pin 1=0
pin 2=2.52
pin 3=5.14

[bleed4me]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

Rechecked DU4


DU4
AMC1117
F0720F
PIN 1= 0
PIN 2=.67
PIN 3= 3.32

[budm]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

Rechecked DU4


DU4
AMC1117
F0720F
PIN 1= 0
PIN 2=.67
PIN 3= 3.32

Can I get good closed up pictures of this DU4 so I can see how the 3 legs are connected?
Looking at this picture: https://www.badcaps.net/forum/attach...6&d=1454392483
The DU4 looks to be an Adjustable 1117.

[bleed4me]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

Absolutely... As soon as I get off work I will get those pictures posted for you.

[bleed4me]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

Getting that picture was trickier than I thought it would be. Things sure do look different when under a magnifying glass. I also figured I would put DU1 on the list as well being that I left it out

DU1
AZ7805T
E1
718G70
PIN 1= 11.86
PIN 2=0
PIN 3= 5.06

I also rechecked the voltages on DU4 and nothing as changed.

[Nick's Tvs]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

My working set has the following readings for DU4

Pin1: 0.0v
Pin 2:1.24V
Pin3: 3.3v

Pin 2 is off for you. It doesn't look adjustable. DL6 and DCE11 are on that same 1.24 volt line. Make sure those are ok.

[bleed4me]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

Well I can tell you that DL6 has continuity and .66V on either side and my multimeter has no way to test a capacitor, visually it looks fine thats all I can say.

[budm]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

DU4 is an adjustable based on the two resistor network (one between ADJ and the Output pin, Resistor DR6, and another resistor between ADJ pin and GND, DR10).
The output Voltage can be calculated by knowing the values of those two resistors.

[bleed4me]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

So are you thinking its the resistors or the regulator?

[budm]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

The resistors are for setting the output Voltage, it will be the IC.
You need to get at least two adj type 1117 Regulator ICs (U5 , DU4).
Tricky part will be removing and installing the ICs without disturbing the resistors and caps closed by, so I hope you are good at surface mount repair.

[bleed4me]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

There is only one way to find out I guess
does this link look about right?
http://www.digikey.com/product-detai...4-5-ND/1677149
or
http://www.digikey.com/product-detai...3PBF-ND/890204

[budm]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

Either one will be fine.

[bleed4me]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

Parts have been ordered, will report back with results as soon as they come in.

[budm]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

BTW, can you take the resistance reading between pin 2 and GND of DU4?

[bleed4me]

Re: Vizio GV47LFHDTV10A No Picture No Sound Fix

As soon as I get home I can get that for you... This wouldn't be about amp rating on that ic would it?