Vizio M65-C1 - no picture, help!

[jaw3]

Hi,

This is my first post here...

Last night my TV broke. I was streaming a show and the TV froze. When I attempted to turn it off/and back on all I get is a black screen. The power led indicator goes on for about 20 seconds, then it blinks 15 times and the TV restarts... it does that again and then it powers down. I don't see anything at all on the screen, no logo or anything at all.

I tried the suggestions from the Vizio website including unplugging, holding the power button for 30 seconds and plugging back in. No differance.
I unplugged overnight and no change.

So, I took it apart and so far I cannot see any obvious damage. I followed some advice from a YouTube video and measured the following voltages from the output pins on the power board:

CN9102
Pin / Listed on Key / Actual when plugged in / Actual Powered on
2 / +5V +3.5 / 0 / 5.12
4 / +12V / 19.08 / 19.08
6 / +12V / 19.08 / 19.08
8 / +12V_A / 19.08 / 19.08
10 / GND / 0 / 0
12 / GND / 0 / 0
14 / PS_ON / 0 / .006
16 / DIM / 0 / .009

CM9101
Pin / Listed on Key / Actual when plugged in / Actual Powered on
1 / +5V +3.5 / .001 / 5.118
3 / +12V / 19.08 / 19.06
5 / +12V / 19.08 / 19.06
7 / +12V_A / 19.08 / 19.08
9 / GND / 0 / .002
11 / GND / 0 / .002
13 / 3D / .001 / 0
15 ON-OFF / .001 / .157

CM9203
Pin / Listed on Key / Actual when plugged in / Actual Powered on
2 / DIM / 0 / 3.32
4 / +12V / 19.08 / 19.08
6 / GND / 0 / .005
8 / GND / 0 / .005
10 / +24V / .001 / 24.65
12 / +24V / .001 / 24.54
14 / +24V / .001 / 24.53

CM9201
Pin / Listed on Key / Actual when plugged in / Actual Powered on
1 / ON-OFF / 0 / .03
3 / 3D / 0 / 0
5 / GND / 0 / 0
7 / GND / 0 / 0
9 / GND / 0 / .002
11 / +24V / .001 / 24.52
13 / +24V / .001 / 24.52

As far as I can tell these voltages look ok. Are they?

The only other thing I noticed is when I tested the long transistors (I think they are called that?) for continuity there was only one that beeped... it is in the picture: FB9202

If there are any suggestions for further troubleshooting I would really like to save this TV... I don't have the money to buy a new one right now... thanks for your help!

[nomoresonys]

Re: Vizio M65-C1 - no picture, help!

Looks like a couple screws that hold down and ground the powerboard are missing, could try replacing those, also PS_ON looks too low which doesn't seem right because you have the 12 v which is 19 on this one.

[jaw3]

Re: Vizio M65-C1 - no picture, help!

I took those screws out to take the board out and look at the bottom and was lazy and only put two back in so it would be grounded when I tested further....
Does the PS_ON reading give any clues of what to look for next?

[budm]

Re: Vizio M65-C1 - no picture, help!

Do you have about 380 ~ 400 Vdc on the main filter caps (3 black caps laying on the side) when measure right between the two legs of the cap when TV is turned on.
Are you 100% sure the PS-ON only showing 14 / PS_ON / 0 / .006?
The switched +24VDC is working and it will NOT be coming on if the PS-ON is only 0.006V.
15 ON-OFF / .001 / .157, no BL-ON either, may be you should recheck this one also.

[jaw3]

Re: Vizio M65-C1 - no picture, help!

Thanks budm,
I rechecked the PS-ON and I did make a mistake. It is reading 3.68 with the power on
Pin 15 is reading .149 with the power on, so it is close to what I got the first time (not quite sure why there would be a slight difference...).
The 3 black caps read 19.09 DC volts -- is that what you are asking or did I set my meter to the wrong setting?

[nomoresonys]

Re: Vizio M65-C1 - no picture, help!

Could be that the BL_ON signal is not being sent from mainbord.

[neilc6]

Re: Vizio M65-C1 - no picture, help!

ON/OFF is the backlight on signal. m series has bga iisues. try heating the main board with a hair dryer and see if it turns on

[nomoresonys]

Re: Vizio M65-C1 - no picture, help!

ON/OFF is the backlight on signal. m series has bga iisues. try heating the main board with a hair dryer and see if it turns on

YES I know it's .157 TOO LOW.

[jaw3]

Re: Vizio M65-C1 - no picture, help!

Where specifically should I point the hair dryer? I'm not familiar with the names of the boards...

[budm]

Re: Vizio M65-C1 - no picture, help!

The main board on the right where the Video/Audio connectors are.

[jaw3]

Re: Vizio M65-C1 - no picture, help!

Thanks...
Should I heat it from the top or bottom? I just took out the screws that hold it on and the back is covered with some sort of residue. Does it look normal?

[jaw3]

Re: Vizio M65-C1 - no picture, help!

After doing some research on "re-flowing" I have some questions before I attempt this...
first, it seems like a heat gun is recommended instead of a hair dryer, right?
also, I need to remove the heat-sink and aim the heat right at the chip, right?
besides that, I am wondering if that residue in the picture on my last post is just excess flux, or something to be worried about that could be contributing to my problem? Thanks!

[neilc6]

Re: Vizio M65-C1 - no picture, help!

Hair dryer is a test to confirm you have failure in the BGA solder balls on the processor. Heating it up may expand the joints to make contact for the tv to power up. Proper repair is to have the processor reballed. I've only baked boards twice and the problem came back after a couple of weeks (PS3 and a laptop motherboard).

[jaw3]

Re: Vizio M65-C1 - no picture, help!

I heated up the main board with a hair dryer and powered it on. No change at all.
I also cleaned up the residue I had mentioned with some isopropyl alcohol. No change at all (except it is cleaner)...

Any suggestions on what to try next?

[neilc6]

Re: Vizio M65-C1 - no picture, help!

Well your main board isn't generating the ON/OFF signal required to turn on the backlights. You will need to get it repaired or replace it.

[nomoresonys]

Re: Vizio M65-C1 - no picture, help!

Should be a white sticker on top of mainboard the one with video/audio connectors, what is the top set of letter and numbers? it's about 15 digits long.

[jaw3]

Re: Vizio M65-C1 - no picture, help!

So, I am looking for this main board and it may not be easy to find. I don't feel like my TV is that old, but maybe it is -- at least for sourcing parts.... any suggestions on where to find parts? I have looked at ShopJimmy, eBay, others that turned up in the Google search.... everyone is out of stock

Anybody here have one of these?
I am also open to repair shop suggestions where I could bring or send the board in for repair...

The board number is: 715G7288-M02-000-005T
The white sticker says: GXFCB0TK0009020X V1.0.6 1537
The serial number on my M65-C1 TV is: LTCASNAR3151318

Thanks!

[budwich]

Re: Vizio M65-C1 - no picture, help!

My guess is that the "12v" isn't 12v for a reason... possibly because where it goes is basically "broken" meaning it is leaving the voltage supply "unloaded"... you might try tracing that connection from the power board to where it goes and see what's up.

[nomoresonys]

Re: Vizio M65-C1 - no picture, help!

See if that's a match, best way is to call or email and give them your numbers, note it says if you are not certified there is no cash refunds: https://www.tvpartsguy.com/vizio-m65...56txfcb0qk027/

[nomoresonys]

Re: Vizio M65-C1 - no picture, help!

Some of the vizios are labeled wrong the 12 volt is normal at 19, hence my reply in post #2.