Vizio M65-C1 No Picture, Backlight or Sound, External LED Working

[Cajun Caps]

Hi All From Texas,

I have searched the forums and believe I have a bad mainboard after testing my power supply and coming across this thread where the OP had low On/Off voltage on Pin 15 (+0.149V~+0.157V) of CN9101/02.

https://www.badcaps.net/forum/showthread.php?t=80093


If someone does not mind looking over my results and reassuring me that this is indeed the case and the mainboard is bad, it would be much appreciated!!


CN9101/CN9102
'Standby' and 'On' Columns = All Cables Plugged In

*While the PCB key states 12V for CN9101/02, it is wrong and should be +19V, which is reflected below.

Pin #/PCB Key/ STANDBY/ ON (Under Load)
1___+5V/+3.5V___+5.11V___+5.11V
2___+5V/+3.5V___+5.11V___+5.11V
3___+19V_______+19.07V__+19.05V
4___+19V_______+19.07V__+19.05V

5___+19V_______+19.07V__+19.05V
6___+19V_______+19.07V__+19.05V
7___+19V_A_____+19.07V__+19.06V
8___+19V_A_____+19.06V__+19.07V

9___GND__________0.00V____0.00V
10__GND__________0.00V____0.00V
11__GND__________0.00V____0.00V
12__GND__________0.00V____0.00V

13___3D __________0.00V____0.00V
14___PS_ON______+0.081V__+3.653V
15___ON/OFF_____+0.015V__+0.134V
16___DIM________+0.009V__+3.290V

CN9201/CN9203

'NC' = Not Connected By Manufacturer

Pin #/PCB Key/ STANDBY/ ON (Under Load)
1___ON/OFF______NC_________NC
2____DIM_________NC_________NC
3____3D__________NC_________NC
4___+12V_________NC_________NC

5____GND________0.00V____0.00V
6____GND________0.00V____0.00V
7____GND________0.00V____0.00V
8____GND________0.00V____0.00V

9____GND_________NC________NC
10___GND_________NC________NC
11___+24V______+0.011V__+24.06V
12___+24V______+0.010V__+24.06V

13___+24V______+0.011V__+24.06V
14___+24V______+0.010V__+24.06V

The 3 PSU Main Filter Caps +385V Under Load / No bulging caps that I could see.

Some other things of note that I came across in other threads asking questions.

There is a visible LED light on the mainboard. Mine Is red when plugged in under standby, and 1/2 red 1/2 purple when on. When the tv is turned back off, LED is red only. Must be two LEDS actually.

Symptoms when the TV failed were vertical cascading lines of different colors, then no sound, backlight, video. The external white LED comes on and blinks as normal, then repeats this every few minutes.

SN Rear Outside Cover LTMASNAR1550041
Mainboard Model # 715G7228-M01-000-005K

I was thinking of just sending this in to Nicks Tvs in Arizona for a repair. Anyone have experience with their service?

Thank You guys!

[neilc6]

Re: Vizio M65-C1 No Picture, Backlight or Sound, External LED Working

ON/OFF is the backlight on signal and not going high. Bad main board.

[R_J]

Re: Vizio M65-C1 No Picture, Backlight or Sound, External LED Working

The power supply is ok. the backlight ON/OFF and DIM are not used on the power supply, The main board drives the led driver board. You could have a main board, T-Con or even the panel itself.

Did anyone clean the screen with a liquid cleaner before the problem?

[Cajun Caps]

Re: Vizio M65-C1 No Picture, Backlight or Sound, External LED Working

The power supply is ok. the backlight ON/OFF and DIM are not used on the power supply, The main board drives the led driver board. You could have a main board, T-Con or even the panel itself.

Did anyone clean the screen with a liquid cleaner before the problem?

Nah. No liquid cleaner was used. In fact, I am not sure if it had ever been dusted either. Good thing my cleanliness is not directly related to this item

If there is some further test I can do, I am open to suggestions.

[Cajun Caps]

Re: Vizio M65-C1 No Picture, Backlight or Sound, External LED Working

Nah. No liquid cleaner was used. In fact, I am not sure if it had ever been dusted either. Good thing my cleanliness is not directly related to this item

If there is some further test I can do, I am open to suggestions.

Edit:
Actually it looks as though we have our connections crossed. CN9201/CN9203 ON/OFF and DIM is not used by the PSU, but it is used in CN9101/CN9102 which ends up going to the mainboard. Being late last night, I overlooked that.