sony tcon t400hw01 v3 no picture

[freakaftr8]

so I have found another one of these boards and even though my working board works in this TV this one produces no picture good backlight. The first thing that comes to mind is a dead as15 IC. Can this IC cause no image?

[budm]

Re: sony tcon t400hw01 v3 no picture

I would see if it has voltage test points, VGMA Gamma test points, etc to see what you get. Fuse is good, right? Since you do have working board to do comparison test which will makes it a lot easier.

[freakaftr8]

Re: sony tcon t400hw01 v3 no picture

Yes fuse is good. Vgamma 1 starts at 14v. steadily declined as I go up And then vgamma 11 and 12 which are the last on the list show 0v

[budm]

Re: sony tcon t400hw01 v3 no picture

Are there any voltage test points on the board? I.E. 3V3. 1V8, etc.
Pictures of the board?

[freakaftr8]

Re: sony tcon t400hw01 v3 no picture

Nevermind

Vgamma1 14.8v
Vgamma2 1.8v
Vgamma3 10.0
Vgamma4 9.44
Vgamma5 9.361
Vgamma6 7.081
Vgamma7 6.096
Vgamma8 4.558
Vgamma9 4.188
Vgamma10 3.4
Vgamma11 2.2
Vgamma12 0.3

I might add that after two or three minutes of the TV being on it shuts down with a 12 blink Code

[freakaftr8]

Re: sony tcon t400hw01 v3 no picture

looking for voltage test points now

[freakaftr8]

Re: sony tcon t400hw01 v3 no picture

What's with vgamma 2 having a low voltage?
Also noticed it's fluctuating all over the place between 1.2 and 1.4v.

[freakaftr8]

Re: sony tcon t400hw01 v3 no picture

Here the board and but seem to be getting 1.8 2.5 3.3 12 volts and other various voltages but I have noticed that if you look at the picture the very lowest Coil there's nothing. It would be at the bottom of the board. Sorry the pictures are upside down

also I noticed if I leave one side the panel unplugged it turns white so obviously its getting voltage of some type

[budm]

Re: sony tcon t400hw01 v3 no picture

Those 3 coils are for switching power supplies. There should be VGL (-), VGH (+) test points on the board some where which I do not remember what they should be.
You can look up the spec sheet for U201, 202, and 203 to see how they function.

[freakaftr8]

Re: sony tcon t400hw01 v3 no picture

Vgl1 is reading -5.999vdc
Vgh1 is reading 30.0vdc

[budm]

Re: sony tcon t400hw01 v3 no picture

Tom66 can tell you more as to what they should be.
According to this, your Voltage is about right:
https://cdn.badcaps-static.com/pdfs/...6c316493a3.pdf

[budm]

Re: sony tcon t400hw01 v3 no picture

BTW, what did you find as far as the voltage comparison readings between the two boards?

[freakaftr8]

Re: sony tcon t400hw01 v3 no picture

Hard to tell. This board is a different version that is interchangeable in this sony. I bought it off eBay cheap. there are two different boards that were supplied with this TV the one that you see now is the earlier of the two boards then there was a change in the model year and they supplied the other board and I'm having a problem with but I thought I'd give a go at this kind of board Since I'm waiting on my voltage regulators for the other t-con board

[freakaftr8]

Re: sony tcon t400hw01 v3 no picture

So is vgamma 2 supposed to be low and bouncing around a few tenths of a volt?

[freakaftr8]

Re: sony tcon t400hw01 v3 no picture

Well looked all over the forums about gamma ics and it seems that when there's a dead spot in the readings it most certainly is bad. Just want to get a perspective before replacing it just in case there's a chance this is normal.

Just to recap. .

I have no picture just backlights on this tcon. Shuts down with error 12. Tv is fine. Works well with other tcon.

Tv model is kdl-46xbr6.

[freakaftr8]

Re: sony tcon t400hw01 v3 no picture

Well replaced AS15-F. Still no picture. Oddly all my gamma readings are now correct. Any ideas? Looks like voltages are all there except the coil on the very bottom.

[freakaftr8]

Re: sony tcon t400hw01 v3 no picture

does anyone have spec sheets on this board? I believe it's sending voltage to the panel because I can pull one ribbon cable off in the other side turns white unlike a completely dead t-con. So obviously the video signal is blanked out

[budm]

Re: sony tcon t400hw01 v3 no picture

You need to locate the spec sheets of those 3 ICs to see what they are and how they function.

[freakaftr8]

Re: sony tcon t400hw01 v3 no picture

Bud are you talking about u201 u202 and u203? (Seen in first picture in post number 8)

[freakaftr8]

Re: sony tcon t400hw01 v3 no picture

Here's what I got on the IC. Does it make sense to you? I understand is a bias supply voltage ic. Texas instrument Tps65161