Samsung LN40D630/BN96-19438A main board noise

[Plane Nuts]

Re: Samsung LN40D630/BN96-19438A main board noise

I don't know if I am on to something but Looking at the Board each IC seems to feed power to the large chip located at the bottom of the picture, and looking at the datasheet of that chip they run at 1.8V.... however there is no change in voltage in both situations (working or not)

[Diah]

Re: Samsung LN40D630/BN96-19438A main board noise

IC204 and IC202 are both the same Z1031AI, I also noticed that putting my probe on the COMP pin gives varying results (from .8 to 1.7) and the screen will act up with interference lines and stay until it resets itself, possibly normal? due to what I can induce into it. and Although IC 204 seems to have odd value, it is not in the area Is affected by applying heat this area is between IC 202 and IC204

its normal.. this regulator are fine COMP to AGND-0.3V to 6V range

edit : just do please the test i asked at my post 19

[Plane Nuts]

Re: Samsung LN40D630/BN96-19438A main board noise

Diah, I will gladly do test in post 19 however please clarify as I am not sure what you want me to do exactly.

[Diah]

Re: Samsung LN40D630/BN96-19438A main board noise

Diah, I will gladly do test in post 19 however please clarify as I am not sure what you want me to do exactly.

sorry.. wrong advice. your set built in t-con.

[Plane Nuts]

Re: Samsung LN40D630/BN96-19438A main board noise

I don't know if I am on to something but Looking at the Board each IC seems to feed power to the large chip located at the bottom of the picture, and looking at the datasheet of that chip they run at 1.8V.... however there is no change in voltage in both situations (working or not)

Diah, any thoughts on this? you might have missed it

[Diah]

Re: Samsung LN40D630/BN96-19438A main board noise

Diah, any thoughts on this? you might have missed it

the both are the DC to DC circuit we talked on before.. they feed not only main IC but RAM too as one of them can support to 3A.

i am just afraid that panel pull over currents and its the fault.. because here on this forum before over 5 years some report the panel issue.

how ever its not my way.. but try packing or really heat 275 degree all BGA ICs you have include the T-CON parts.. other wise its very hard to know unless you have working main boards under hand to compare.

[Plane Nuts]

Re: Samsung LN40D630/BN96-19438A main board noise

To give a status update, decided to clean the board with Alcohol once again, but a bit more aggressively and used shop air to dry off. It now turns on normally now on the the next issue, image quality. As you can see in the picture, columns of pixels seem to be offset, according to the previous posts once again point to the main board, any magical fix? or way of knowing it really is the main board and not the T-Con? it is looking like a good blast of heat with the heat gun to possibly reflow something as a last desperate measure as Diah mentioned before I part out the rest, in case someone is interested in parts.

[Diah]

Re: Samsung LN40D630/BN96-19438A main board noise

put this HD test picture on USB and play it on the tv... show the result

[Plane Nuts]

Re: Samsung LN40D630/BN96-19438A main board noise

put this HD test picture on USB and play it on the tv... show the result

See attached pictures, I was not able to take a picture of the complete screendue to the position on my workbench, however i confirm it is the same across the screen.

this was put up via my laptop and HDMI Cable if it makes a difference

I also have to say thank-you for taking the time to help with this.

[Diah]

Re: Samsung LN40D630/BN96-19438A main board noise

its white offset.... BGA on main board.. go more aggressively with BGA ICs