VIZIO M65-C1 Does Not Turn On

[Mulp]

Hi All,

I am having an issue with my Vizio M65-C1 where it does not turn on. When I plug it in the stand by light on bottom left of screen turns on (white) then fades away. If I press the power button it turn back on and then fades until it is super dim.

When I remove cover, there are no illuminated leds on the main board, I've seen others with a red/blue led that turns on.

I've done some research and what is interesting is my voltages all seem slightly different from other people. For example +5/3.5v is 3.48V when on which is different from others on here. My +24V also shows up as 16.25V. Hoping someone can point me in the right direction. Would love to replace some broken capacitors or diodes but if entire board needs replacing that is good to know as well!

I am including the measurements with the TV OFF (plugged in) then ON

CN9101 --------------- OFF ; ON
PIN 1 - +5V/+3.5V ---- 0V ; 3.47V
PIN 3 - +12V ------- 13.5V ; 12.87V
PIN 5 - +12V ------- 13.5V ; 12.86V
PIN 7 - +12V_A -- 13.51V ; 12.87 V
PIN 9 - GND ------------ 0V ; 0V
PIN 11 - GND ----------- 0V ; 0V
PIN 13 - PS_ON ------- 0V ; 2.49V
PIN 15 - DIM ------------ 0V ; 2.49V

CN9102 ---------------- OFF ; ON
PIN 2 - +5V/+3.5V ----- 0V ; 3.48V
PIN 4 - +12V ------ 13.51V ; 12.89V
PIN 6 - +12V ------ 13.51V ; 12.88V
PIN 8 - +12V_A ---- 13.5V ; 12.89V
PIN 10 - GND ---------- 0V ; 0V
PIN 12 - GND ---------- 0V ; 0V
PIN 14 - PS_ON ------ 0V ; 0V
PIN 16 - DIM ----------- 0V ; 0.04V

CN9201 -------------- OFF ; ON
PIN 1 - ON/OFF ------ 0V ; (NO WIRE)
PIN 3 - 3D -------------- 0V ; (NO WIRE)
PIN 5 - GND ----------- 0V ; 0V
PIN 7 - GND ----------- 0V ; 0V
PIN 9 - GND ----------- 0V ; (NO WIRE)
PIN 11 - 3D ------------ 0V ; 16.25V
PIN 13 - ON/OFF ---- 0V ; 16.26V

CN9203 -------------- OFF ; ON
PIN 2 - DIM ------------ 0V ; (NO WIRE)
PIN 4 - +12V ----- 13.51V ; (NO WIRE)
PIN 6 - GND ----------- 0V ; 0V
PIN 8 - GND ----------- 0V ; 0V
PIN 10 - +24V --------- 0V ; (NO WIRE)
PIN 12 - +24V --------- 0V ; 16.26V
PIN 14 - +24V --------- 0V ; 16.27V

[Storyteller12]

These TVs have issues with the main board. Specifically the BGA chips under the large heatsink.

they get to hot and the solder balls expand and short out

[diif]

Yes, it's likely to be a BGA issue but the balls do not expand and short out. The solder joints crack due to expansion and contraction from it's heating/cooling cycle and the the lack of lead in the balls.

[Storyteller12]

They expand as well because there to hot. They crack when cooling after being on and hot for a while. But they short out because they expand. If they just cracked there wouldn’t be shorted. It just wouldn’t make connection.

[diif]

No, there is no shorting out due to expansion, the expansion is minimal, it's cracking causing no or intermittent connection.
if there is any shorting it is due to tin whiskers, which i have encountered once on a PS4.

[Storyteller12]

Not trying to argue as I’m here to learn. But they do short out. Nicks TVs did a video where he shows its shorted on the caps next to the BGA chips. After reflowing them the short is gone and the tv works again.

[Mulp]

Just a quick update.

Given the replies I felt like the issue is probably the main board.

I thought I would just try baking the mainboard before purchasing a replacement online so I removed the mainboard, covered everything apart from the bga chips on top and bottom of board with two pieces of cardboard and baked in oven. I used a thermometer to try and keep the heat to ~350 for 8 minutes. Hit a high of 370. Surprisingly that seemed to have done the trick. I heard this is still a temporary fix so I've kicked the can down the road for another couple months it seems.

Thanks for all the help everyone!

[nomoresonys]

If you can get a fan blowing on your bga it will last a lot longer.

[Mulp]

If you can get a fan blowing on your bga it will last a lot longer.

thanks a bunch, that’s super helpful!