Vizio VO370M LCD

[bjorkson]

I have another TV I pick up, when you turn it on, looks like everything is negative. Picture looks like a negative roll of film. As you can see from the picture. I have rule out the t-con board. This model have the inverter board and power supply built in as one. The backlight powers on fine when you turn on the tv. There are 5 inverter transformer on this board, could a bad transfomer cause the picture screen to be negative? Any thoughts?

[Caleb]

Re: Vizio VO370M LCD

How did you rule out the tcon? This appears to be a failed Gamma Ic which usually resides on the tcon although I suppose they could have put it on the main board. Doesnt have anything to do with the inverters at all.

[bjorkson]

Re: Vizio VO370M LCD

At first, I suspect it was the Tcon board, so I order a new one and it still does the same thing. So is the Gamma IC on the main board? What does it look like? and is there a way for me to test it?

[budm]

Re: Vizio VO370M LCD

Can we see the pictures of the T-CON board? Is it LG or AUOPTO brand? It sure looks like bad Gamma voltage to me too. Is the T-CON good for sure? There should be test points on the T-CON board to test the Gamma ref voltages.

[bjorkson]

Re: Vizio VO370M LCD

Yes, here's the picture of the Tcon board.

[budm]

Re: Vizio VO370M LCD

What is the P/n printed on the sq IC with about 30 pin to the right of the large IC in the middle?

[bjorkson]

Re: Vizio VO370M LCD

Rm5101 aqf994.1

[bjorkson]

Re: Vizio VO370M LCD

Correction: RM5101 AOF994.1

[budm]

Re: Vizio VO370M LCD

That U500 is the Gamma IC AS15.
http://assets.shopjimmy.com/media/ca...5537t05c09.jpg

[bjorkson]

Re: Vizio VO370M LCD

OK...so you think I brought a bad Tcon board then? Got it used on ebay.

[budm]

Re: Vizio VO370M LCD

That is very commonly failed Gamma IC, if you search the thread with "AS15" you will see lots of threads. I hope you can return the board.

[bjorkson]

Re: Vizio VO370M LCD

Ok budm...thanks for all your help. Will try to return it and buy another one. Will advised once I get another one in.

[bjorkson]

Re: Vizio VO370M LCD

Ok, so I order another Tcon board from ShopJimmy and install it, didn't change a thing. Problem still there, could I possible have another bad Tcon board? ShopJimmy is very reliable on their board. Could I have a bad main processor board causing this? Any thoughts?

[tom66]

Re: Vizio VO370M LCD

You can test the gamma voltages if you want.

[bjorkson]

Re: Vizio VO370M LCD

Tom, how can I test the gamma voltages?

[tom66]

Re: Vizio VO370M LCD

Do you see the points near AS15 IC marked VG1,VG2,VG3...?
Plus VCOM, AVDD.

Test VG1...VGxxx the voltage should be monotonic (rise or fall, not both) from 0 to AVDD. VCOM should be approx 1/2 of AVDD. And AVDD should be around 14 to 18V.

[bjorkson]

Re: Vizio VO370M LCD

Ok...let me test it this weekend when I have time. Thx