Vizio m550nv orang light and no turn on

[audiofreak19]

Re: Vizio m550nv orang light and no turn on

if you dont mind me asking how to i test those. what should the poles read one gnd one voltage and what would the other read.

[freakaftr8]

Re: Vizio m550nv orang light and no turn on

Black pole on chassis ground red lead on the biggest pin opposite of the three pins. Write down u1 u2 u3 etc. Write what voltage you get then writw or post a clear pic of the board or write what each regulator says on it.

meter is set on dc voltage

[audiofreak19]

Re: Vizio m550nv orang light and no turn on

All of the ones labeled u1 U2 ect. Are the box with 4 legs on each side. I have heard of someone having to replace one of these but I don't know which one they had to replace or hot to test it.

[audiofreak19]

Re: Vizio m550nv orang light and no turn on

Anyone know how I can test these mosfets or what ever they are.

[catman25]

Re: Vizio m550nv orang light and no turn on

Looking for a little help . I am a amateur but pretty good with diy . I have a vizo with no picture ,no sound and wont turn off unless I unplug it . I tested the regulators and these are the reading
u8 2.4-3.3-5.12
u9 0-1.18-2.2
u7 .03 -1.03-2.05
u33 1.27 - 205 -5.10

Im suspecting the u33 issue but curious can I replace this with any auto regulator ?
Freeze spray did not work unless I did that wrong .
Also I picked up part lm317t adjustable regulator ? Would this work or must I use a 1117 format ?

[budm]

Re: Vizio m550nv orang light and no turn on

u8 2.4-3.3-5.12: 1.25V ref + 2.4 = 3.65V bad. Voltage between ADJ pin and Output pin should always be 1.25V
u9 0-1.18-2.2 little low
u7 .03 -1.03-2.05: looks bad, min is 1.25V, this can be due to low input voltage of 2.05V
u33 1.27 - 205 -5.10: 1.25V ref +1.27 = 2.5V, Bad
So the rule is, the voltage between the ADJ pin and the Output pin should always be 1.25V +/-2%, the expected output voltage should be = 1.25 + Adj voltage
Also try to show more resolution of the voltage with at least 2 decimal points.
See link below for 1117 from Digikey.
LM317 is not low drop out reg.

[vinceroger69]

Re: Vizio m550nv orang light and no turn on

ignore wrong thread

[catman25]

Re: Vizio m550nv orang light and no turn on

u8 2.4-3.3-5.12: 1.25V ref + 2.4 = 3.65V bad. Voltage between ADJ pin and Output pin should always be 1.25V
u9 0-1.18-2.2 little low
u7 .03 -1.03-2.05: looks bad, min is 1.25V, this can be due to low input voltage of 2.05V
u33 1.27 - 205 -5.10: 1.25V ref +1.27 = 2.5V, Bad
So the rule is, the voltage between the ADJ pin and the Output pin should always be 1.25V +/-2%, the expected output voltage should be = 1.25 + Adj voltage
Also try to show more resolution of the voltage with at least 2 decimal points.
See link below for 1117 from Digikey.
LM317 is not low drop out reg.

*** would it seem like there is more to the "fix" then regulators ? Any other things that would typically cause these reading same symtoms ?

[catman25]

Re: Vizio m550nv orang light and no turn on

I did want to add I have a new main board coming and just trying to fix this one to possibly return new one coming . Just hope its the main board and nothing else

[budm]

Re: Vizio m550nv orang light and no turn on

It looks like you do have some bad regulators.

[audiofreak19]

Re: Vizio m550nv orang light and no turn on

So opening up my tread again. I finally just bought another main board off ebay and hooked it up and it did the same thing. I'm wondering more now if it's something on the power supply cause in another forum a guy was having the same problem but he just went and bought a new power supply instead of troubleshooting it down to the component level. On the main power connectors it gets the 5v standby voltages when it's plugged in. But after about 10 min of the flashing logo the other connectors with the 18v and the 12v and bk light and power on get juice all out of no where. I tried testing the 4 diodes on the heat sink ad they seem to test fine they all test the same. I'm not sure what else to do to avoid spending the money on a power supply.

[audiofreak19]

Re: Vizio m550nv orang light and no turn on

Another thing I have been thinking about. So it could be a voltage regulator on the power supply gone bad cause when I got the tv the main board had a partially melted smd capacitor. So if a voltage regulator went bad and sent more voltage then supposed to causing it to melt. I don't know I'm just brain storming.

[Mtrprts]

Re: Vizio m550nv orang light and no turn on

Please help. I also have m550nv. No turn on. Just orange vizio light. All readings on power board that are supposed to read 5volt, read correctly. All pins showing 12 volts read zero. I have replace power board and get exact same readings. Any suggestions?

[Louis82]

Re: Vizio m550nv orang light and no turn on

Hello,

Have you guys been able to find what the problem could be on this main board. I have the same symptom, orange/amber light is on but will not change to white. Tv not turning on.

[Louis82]

Re: Vizio m550nv orang light and no turn on

Budm, I'm working on this Vizio Tv M550NV. Can you look at these readings and tell me which one seems defective to you. Thanks in advance.

IC G5684
Pin 1: 1.8V
Pin 2: 0.0V
Pin 3: 5.0V
Pin 4: 5.1V
Pin 5: 1.2V
Pin 6: 1.2V
Pin 7: 0.8V
Pin 8: 0.8V

IC G5693
Pin 1: 5.1V
Pin 2: 0.8V
Pin 3: 0.0V
Pin 4: 0.8V
Pin 5: 5.0V
Pin 6: 0.0V
Pin 7: 1.8V
Pin 8: 5.1V

IC G5692
Pin 1: 5.1V
Pin 2: 0.8V
Pin 3: 0.0V
Pin 4: 0.8V
Pin 5: 5.0V
Pin 6: 0.0V
Pin 7: 2.5V
Pin 8: 5.1V


IC G5692
Pin 1: 5.1V
Pin 2: 0.8V
Pin 3: 0.0V
Pin 4: 0.8V
Pin 5: 5.0V
Pin 6: 0.0V
Pin 7: 3.3V
Pin 8: 5.1V

[Louis82]

Re: Vizio m550nv orang light and no turn on

Bump

[budm]

Re: Vizio m550nv orang light and no turn on

OK, I will download the spec sheets for them first, but so far the outputs look to be about right:
3.3V, 2.5V, 1.8V, and 1.2V which are the typical Voltages.

[Louis82]

Re: Vizio m550nv orang light and no turn on

Thank you Budm.

[budm]

Re: Vizio m550nv orang light and no turn on

OK, these are the spec sheets for the Buck converter ICs.
The outputs look right, if you want to really find out for sure then you will need to check the two resistors that are used to set the output Voltage, see the spec sheets for details.