Hey guys. I have a 65" Vizio M65-C1 UHD 4K TV that has no power. I've done a lot of research on this model and some common problems that other people seem to have is unfortunately not applicable to me and my TV as I have different symptoms. I've documented all of my measurements and behavior I've noticed as follows:
Symptoms:
1. TV does not power on.
2. Power light in bottom right corner (if facing display) briefly lights for a moment upon plugging in power and fades to black. No response from power button or remote control.
3. Purple/Red LED located on the main board does nothing at any point. (I understand it's supposed to flash and then remain solid if working properly. Mine does nothing at all.)
Below are the measurements I have taken. The first set is connected but powered OFF and the second set of measurements is while powered ON:
Something else I can add based on what I saw was asked in other threads based on this model is that the 3 large caps (C9804, C9805, and C9823) read 390.4V
I did come across this YouTube video where a guy had a problem with a resistor and a diode located on the power board and changing them fixed his problem.
The video is based on the symptoms of the 19V line fluctuating/not steady and a flashing purple light on the main board. I don't share either of those symptoms, but I went ahead and checked the two components anyway.
The resistor on the bottom of my power board R9114 is reading in the ~1 mega ohms range just like his was in the video while the one above it R9135 is reading as his does about 8.9 kilo ohms. Should I change this resistor? R9114? It reads the same as the guy's does in the video and he changed it. Apparently R9114 is supposed to read about 8.9 kilo ohms like R9135 does.
The diode marked D9103 checked out ok, passing voltage one way but not the other.
That's really all that I can tell you about the TV. While I'm not a complete newb, I am still learning a lot about TV repair and with my limited knowledge I think it's a main board problem.
I've already did some initial searching for the replacement board just to see if they are even available and it seems like there are a few on ebay, but if at all possible, I'd like to repair the component(s) that are at fault if it is indeed the main board. I haven't yet come across a thread/video where someone fixed a main board problem yet although I did see a thread that made a reference to reflowing the processor on the main board.
Can someone take a look at what I've posted here and guide me on what I can do from here to repair this TV? I've attached pics, but let me know if you need more.
Thanks
Symptoms:
1. TV does not power on.
2. Power light in bottom right corner (if facing display) briefly lights for a moment upon plugging in power and fades to black. No response from power button or remote control.
3. Purple/Red LED located on the main board does nothing at any point. (I understand it's supposed to flash and then remain solid if working properly. Mine does nothing at all.)
Below are the measurements I have taken. The first set is connected but powered OFF and the second set of measurements is while powered ON:
Code:
-------------------------------------------------------------------------- Measurements taken with only main board, power board, power button board, and power LED indicator connected [B][U]while OFF:[/U][/B] [B][U] CN9101[/U][/B] [B][U]Pin Marking[/U][/B] [B][U]Measurement Taken[/U][/B] 1. +5V/3.5V 5.08V 2. +12V 19.05v 5. +12V 19.05v 7. +12V_A 19.05v 9. GND 11. GND 13. 3D 0 15. ON/OFF 39-42mV (fluctuating) [B][U]CN9102[/U][/B] [B][U]Pin Marking[/U][/B] [B][U]Measurement Taken[/U][/B] 2. +5V/3.5 5.08V 4. +12V 19.05V 6. +12V 19.05V 8. +12V_A 19.05V 10. GND 12. GND 14. PS_ON 76.1mV 16. DIM 8.9mV [B][U]CN9203[/U][/B] [B][U]Pin Marking[/U][/B] [B][U]Measurement Taken[/U][/B] 1. N/C 3. N/C 5. GND 7. GND 9. N/C (but marked GND) 11. +24V 7mV 13. +24V 7mV [B][U]CN9201[/U][/B] [B][U]Pin Marking[/U][/B] [B][U]Measurement Taken[/U][/B] 2. N/C 4. N/C 6. GND 8. GND 10. N/C (but marked +24V) 12. +24V 7mV 14. +24V 7mV --------------------------------------------------------------------------
Code:
Measurements taken with only main board, power board, power button board, and power LED indicator connected [B][U]while ON:[/U][/B] [B][U] CN9101[/U][/B] [B][U]Pin Marking[/U][/B] [B][U]Measurement Taken[/U][/B] 1. +5V/3.5V 5.08V 2. +12V 19.05v 5. +12V 19.05v 7. +12V_A 19.05v 9. GND 11. GND 13. 3D 0 15. ON/OFF 153mV (and drops slowly) [B][U]CN9102[/U][/B] [B][U]Pin Marking[/U][/B] [B][U]Measurement Taken[/U][/B] 2. +5V/3.5 5.08V 4. +12V 19.05V 6. +12V 19.05V 8. +12V_A 19.05V 10. GND 12. GND 14. PS_ON 3.65V 16. DIM 3.33V [B][U]CN9203[/U][/B] [B][U]Pin Marking[/U][/B] [B][U]Measurement Taken[/U][/B] 1. N/C 3. N/C 5. GND 7. GND 9. N/C (but marked GND) 11. +24V 24.26 13. +24V 24.26 [B][U]CN9201[/U][/B] [B][U]Pin Marking[/U][/B] [B][U]Measurement Taken[/U][/B] 2. N/C 4. N/C 6. GND 8. GND 10. N/C (but marked +24V) 12. +24V 24.26V 14. +24V 24.26V -----------------------------------------------------------------------
I did come across this YouTube video where a guy had a problem with a resistor and a diode located on the power board and changing them fixed his problem.
The video is based on the symptoms of the 19V line fluctuating/not steady and a flashing purple light on the main board. I don't share either of those symptoms, but I went ahead and checked the two components anyway.
The resistor on the bottom of my power board R9114 is reading in the ~1 mega ohms range just like his was in the video while the one above it R9135 is reading as his does about 8.9 kilo ohms. Should I change this resistor? R9114? It reads the same as the guy's does in the video and he changed it. Apparently R9114 is supposed to read about 8.9 kilo ohms like R9135 does.
The diode marked D9103 checked out ok, passing voltage one way but not the other.
That's really all that I can tell you about the TV. While I'm not a complete newb, I am still learning a lot about TV repair and with my limited knowledge I think it's a main board problem.
I've already did some initial searching for the replacement board just to see if they are even available and it seems like there are a few on ebay, but if at all possible, I'd like to repair the component(s) that are at fault if it is indeed the main board. I haven't yet come across a thread/video where someone fixed a main board problem yet although I did see a thread that made a reference to reflowing the processor on the main board.
Can someone take a look at what I've posted here and guide me on what I can do from here to repair this TV? I've attached pics, but let me know if you need more.
Thanks
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