Schematic for Sony 320AB03S2LV0.1

[keeney123]

I need a schematic for the above board. It is the Top Bd. that goes directly to the LCD panel. My problem is BY32 is shorted out to 15 Volts. This line is going to some device in the center of the ribbon cable. It does not appear to be going directly to the LCD. I have attached picture of problems I am having. this is in reference to Sony KDL-32LL150. Any help would be appreciated.

[kasfamily]

Re: Schematic for Sony 320AB03S2LV0.1

Show foto the above board and panel marking.

[keeney123]

Re: Schematic for Sony 320AB03S2LV0.1

Here are the above bd with markings for the panel.

[budm]

Re: Schematic for Sony 320AB03S2LV0.1

So one end of the BY32 is connected to the common ground plane? Did you remove it and test the resistance between the two pads?

[keeney123]

Re: Schematic for Sony 320AB03S2LV0.1

I measured the resistance across it at about 10.8K ohms. It is the other side that has 15 volts on BY32. I do not have a schematic. It is a direct short to OP2 pin 4. The other side of the board which has the same identical circuit on BY1 has around 3.23 volt and is "not" directly shorted to OP1 pin 4. C4 and C5 on either end of the board both read a short across each one but I do not know if this is OK. I could not find a pin out or data sheet for OP1, OP2. They are i7814HS. I know they where manufactured by a company in S.Korea that is owned by Samsung. The problem is that I do not have a schematic of this board. So any of the above could be all right or not. I never troubleshoot a LCD screen before, at least not down to component level. I fix this TV about a year ago. It had a bad backlight. I replaced all of them and gave the TV to a friend of mine. She had it for 6 months and it worked fined until one day when I was over to see her and we were watching it and all of a sudden it appeared like you see in the first post. I got a T-con bd from Jimmy's an got the same results. I then got a main bd. from TV Tech Parts out of Huntsville, Al. with the same results.

[budm]

Re: Schematic for Sony 320AB03S2LV0.1

OK, thanks for the explanation, I thought the cap itself is shorted but that is not the case, now I see what you are trying to find out.
I never deal with fixing this board and I doubt very much if we can find the SCH for this board.
The trace does look like it goes to the SMD IC encased on the flexible PCB, that IC is the line driver which may be it is shorted out, that is what I think.

[kasfamily]

Re: Schematic for Sony 320AB03S2LV0.1

Try to interrupt two tracks CKV2 and CKVB2 as in the picture

[keeney123]

Re: Schematic for Sony 320AB03S2LV0.1

Would you tell me what are these two tracks used for and why do I want to interrupt them?
I have a Radio Shack meter that is capable of connection to my netbook and showing and Oscilloscope display, but the Frequency limit is 100K HZ. I need to get finer tip probes for this meter so I do not slip off of anything. Question is how fast are these signals traveling on the screen? If I could see these signals I might be able to tell which one is turning on at the wrong time.

[keeney123]

Re: Schematic for Sony 320AB03S2LV0.1

I ohmed out both IC completely one pin to another and found none of them shorted.

[budm]

Re: Schematic for Sony 320AB03S2LV0.1

I am talking about this IC on the flexible PCB, there should be more than 2.
https://www.badcaps.net/forum/attach...0&d=1401307448

[keeney123]

Re: Schematic for Sony 320AB03S2LV0.1

What a place to put an IC. There are one of those to each cable. I did not know what those were. I had thought they might be a resistor array. I will ohm those out but I will never know what is suppose to be connected or not without a schematic. It will take me some time to do this as I am helping a friend with her trailer. I will let you know how it ohms out.

[keeney123]

Re: Schematic for Sony 320AB03S2LV0.1

Thanks BudM for your support.

[budm]

Re: Schematic for Sony 320AB03S2LV0.1

You may want to read this:
https://www.badcaps.net/forum/showpo...4&postcount=12

[keeney123]

Re: Schematic for Sony 320AB03S2LV0.1

So my understanding is that I have a gate driver problem. It would appear that the gate driver is in a flexible cable that attaches to the side of the screen, but there is no flexible cable on the side of my screen. I have two flexible cables at the top of the screen. The shift registers that turn on the 4098 vertical rows must also have a stop bit as I see 8 bits control 512 binary bits. Also, I did not notice how many horizontal lines the gate driver turns on. My understanding is the proceeding horizontal line turns on the next horizontal line. Therefore I would imagine that this control is build in to the screen itself. As the gate driver only initiates each frame and then it cascades down till all the horizontal and vertical lines have completed the frame?

[keeney123]

Re: Schematic for Sony 320AB03S2LV0.1

I had a bit of time to study this. As I figure each color of each pixel has to be present at 5.64 nano seconds. The shift registers are in the LCD screen. They are serially feed by the source drivers and a clock pulse until all 4098 vertical columns buffers are filled. At the same time the gate drivers are loading the first of the 720 horizontal lines. After the gate driver loads the 1366 pixels with each of its three colors of the first line the source gate buffer is now enabled turning on all the appropriate vertical columns and then the whole process starts again for the second line until all 720 horizontal lines are complete. This then equals one frame of a picture and this will happen 60 frames a second on a 60Hz screen. 120 Frames a second on a 120Hz screen or 240 Frames a second on a 240Hz screen. Thank you Bud M for the info.

[keeney123]

Re: Schematic for Sony 320AB03S2LV0.1

I now believe what happen with this screen was at the horizontal line where the problem occurred it never turned off. What is suppose to happen is that the completion of the present line turns itself off and turns on the next line.
This problem line was never turned off, therefore each proceeding line that was enabled or turned on by the source driver also turned on the line that had problem.