Vizio M65-E0 No Picture, No Sound

[ggil44]

Hi I inherited a Vizio M65-E0 that isn't working. It must have been dropped on the corner because I found that the infrared circuit had a capacitor with one end broken off of the board and some green corrosion around the plug to the main board. I re-soldered the capacitor and cleaned the corrosion well and tried turning the M65-E0 on and I was successful. My problem is that while the back lights come on and appear to perform local dimming there is no picture or sound. It kind of looks like you are looking at the TV through a very dense fog, where changing the input on the remote will change bright spots on the screen only. Any help you can offer to locate the problem is greatly appreciated. Thanks

[EazyBone]

Well you got a main board and a TCON. Are you getting 12v at the TCON fuse?

Try disconnecting one ribbon at a time on the buffer boards and plugging in to see if you get 3/4 a picture. Also inspect the area very closely where it was dropped on the corner.

[ggil44]

Hello EazyBone, I tried disconnecting one ribbon cable at a time from the T-Con to the buffer boards with no change in the display (no picture) except the backlights were a little dimmer. Don't know where the TCON fuse is but at 12v test point got 12.48V. See pictures, Thanks

[nomoresonys]

Fuse is white F101 there by the connector.

[ggil44]

I forgot to add that the IR sensor board had one pin that looked like it got hot. I am enclosing a picture of the back side of the socket as I don't have a good picture of the front. The TV turns off and on with the remote as it should.

[nomoresonys]

This is a pretty decent tcon for testing, with everything hooked up and powered on if you can, that's after you verify the ~12 volts on each side of F101, test the little copper circles, see them there labeled vgh, vgl etc, test all those and report the voltages as in vgh 25 etc. etc.

[ggil44]

Hello nomoresonys, I found F101 and checked voltage to be 12.48v on both side of the fuse. Thanks

[nomoresonys]

Ok, thats good, try those tests in post # 6.

[nomoresonys]

Check if the optical red led is lit on the mainboard.

[lotas]

If it fell, then the impact could cause the processor under the radiator to fall off (the bga soldering was damaged), if there was corrosion, then it could also cause great harm...

[ggil44]

Vizio M65-E0 T-Con voltages:
VGA 7 .01v
VID8 TCON 1.83V
VID1 TCON 1.08V
VCC 3.28V
VGH .78V
V3D3 3.27V
TDCON .02V
VGL .05V
AVDD .86V
SCL 3.27V
WP .1V
SDA 3.27V
J106 STARTING PIN 1 .1, 3.27, 3.27, 0, 0, 3.27V
V12 12.48V

ANYTHING ELSE NOT REPORTED WAS 0v. Regards, Gil

[lotas]

VGH should be around +30v and VGL should be around -10 - 12v., AVDD should be from +13 - 20v

[ggil44]

Everything seems to be in good physical shape. Yes the red light for optical out plug is lit. Thanks for your help.

[ggil44]

Hello Lotas, obviously I wasn't getting those voltages on the T-CON board. Does that suggest a main-board problem or power supply? I'm thinking main-board since the TV powers on and the back lights work.

[EazyBone]

It's hard to ask that question. If the panel is dead, those voltages will be messed up anyway. With a fall like you say on the corner, the screen can be effed and you won't know. This appears nothing to do with power supply, your backlights work and if you checked the PSU voltages, I'm sure they are all fine.

You likely have a panel issue. But yes the main board can cause it, and the TCON.

Try disconnecting one ribbon at a time on each buffer board and from TCON and measure VGL, VGH and VGA and see if the numbers change at all. If you disconnect the shorted part of the screen, those numbers may come up to normal potentially

[lotas]

Hello Lotas, obviously I wasn't getting those voltages on the T-CON board. Does that suggest a main-board problem or power supply? I'm thinking main-board since the TV powers on and the back lights work.

These voltages can be blocked if there is low resistance at their outputs, this could be a short circuit of some kind of ceramic capacitor, either on the T-con itself, or on the buffer strips or in the panel itself...

[Diah]

the title say also NO Sound.. so why you are to T-CON... discommode the 2 ribbon from screen and try to have sound first... then back to solve pivture

[ggil44]

Had to be gone for awhile, voltages on T-CON with each ribbon cable disconnected R disconnected VGL .04v, VGH .73v VGA 0, 0, 0, 0v. L disconnected VGL -10.51v, VGH 30.2v, VGA1, 15.2v, VGA7, 8.1v, VGA8, 6.9V, VGA14, .35v

[lotas]

Had to be gone for awhile, voltages on T-CON with each ribbon cable disconnected R disconnected VGL .04v, VGH .73v VGA 0, 0, 0, 0v. L disconnected VGL -10.51v, VGH 30.2v, VGA1, 15.2v, VGA7, 8.1v, VGA8, 6.9V, VGA14, .35v

Well, where there is no voltage, that half is not working.That is, the left bar or left side has a short somewhere in the power supply.

[ggil44]

Hello lotas, When you say "power supply" are you referring to the main power supply or the T-CON board?