Sony KDL-37V4000 Half Panel Too Bright!

[reessi]

This TV came to me with a full screen solarized (thats how I landed at this forum as many threads on the AS15 Gamma chip blown).

Unfortunatly before I realised the fault I tried removing first one ribbon to left side of panel and then the right.

I noticed that if I dis-connected one the other half would turn white.

I was surprised as alot of people online in youtube videos for other tvs had done this to see if one side was faulty and caused the other side to be brought down. None made the other side dis-appear, some it cured as there was a faulty ribbon to panel. This was not the fault on this tv though. It was the common AS15.

But too late as after re-connecting the left hand side it never worked at all apart from some random vertical coloured lines. The right side got a bit worse but still had some sort of pic. So I replaced the AS15 as it was blazing hot.

Now the right side appeared to work. But still no left. I didn't notice though that it was still too bright as it just showed some white writing briefly at turn on and could not access menu as on left of screen but no washed out black anymore though.

So I replaced the whole T-Conn and now left is perfect and right the same is too bright. Now you see I can access the menu on the left hand side to select a source like laptop and see that right is too bright, this is same on old T-Conn now as I left input selected on laptop and tried that again.

So any ideas why just the right hand side is too bright, can this now be a panel fault or rather the tiny board above?

Also why did disconnecting one ribbon kill the old T-Con even more!

There are these 2 chips -> AS34-G , one on left panel board and one on right. Could this be responsible for the brightness fault for half the screen.

Before buying a new T-Conn card I swapped these chips to see if thats why the left was not displaying. It appeared to not make any difference. I could swap them back and see if the left becomes bright and the right normal.

Could I just have ended up with another faulty T-Conn? The brightness level is same on old card which has the new AS15 on it.

Many thanks - Simon.

[reessi]

Re: Sony KDL-37V4000 Half Panel Too Bright!

I looked at the data sheet for the 2 AS34-G chips, its says TFT Reference driver but I dont know enough to understand what its actually doing, also forgot to say I measured all the VGamm Voltages as explained in this forum. Now on the T-conn card itself is only half the test points, I dont understand why, random as well 1,2,6,7 etc. But on the right driver board for panel is all of them, they measure in increments as another thread said they should and the left panel board has only half in order though but also appear to be normal.

Cheers.

[Moreno83]

Re: Sony KDL-37V4000 Half Panel Too Bright!

Are you sure you only see the random test points? could you provide some pictures using the attachment button? ( Advanced ).

[reessi]

Re: Sony KDL-37V4000 Half Panel Too Bright!

Hi mate, here is a pic off the web of my t conn, when I say random I dont mean all over the board I mean randomly misses some out, see the arrows, one points to the points and the other the labels.

They go as follows:

1,2,6,7,8,10,11,12,13,15,16,17,21,22.

So misses a load out.

Cheers.

[reessi]

Re: Sony KDL-37V4000 Half Panel Too Bright!

sorry forgot to attach.

[reessi]

Re: Sony KDL-37V4000 Half Panel Too Bright!

Well all the Vgam test points are along the top of the left panel board and right panel board and they both test the same either side and are correct as well, moving incrementally. Removing the 2 AS34-G chips, one on the left and one on the right does absolutely nothing to the picture. Still normal on left and brighter on the right.

Any ideas anyone?

Or is that the job of them to match the left and right brightness? I thought if removed then at least something would change.

Cheers.