LG 50PS60 Sound but no picture Ysus board EBR6183001

[tom66]

Re: LG 50PS60 Sound but no picture Ysus board EBR6183001

The signal looks fine to me, but it's not synchronised with the VS_DA point right now. Can you try triggering off VS_DA, using CH1 for VS_DA and as the trigger source, and CH2 as your Y-sustain output? You can try adjusting the TRIGGER LEVEL (making sure trigger source is set correctly and mode is on AUTO) to see if you can get the scope to lock onto the trigger properly.

Your issue with the channel attenuation setting being intermittent isn't uncommon, and can usually be fixed by using contact cleaner on the switch. As you note, you may have to disassemble the instrument to access this part.

[goldbird78]

Re: LG 50PS60 Sound but no picture Ysus board EBR6183001

Just want to make sure I am accessing the correct VS DA test point on the control board. I circled below in red.

[tom66]

Re: LG 50PS60 Sound but no picture Ysus board EBR6183001

That is correct. I am wondering if the signal might not be making good contact; you might want to consider scraping off the "solder mask" in that area to reveal the copper so you can solder a wire to it, carefully.

[goldbird78]

Re: LG 50PS60 Sound but no picture Ysus board EBR6183001

Yeah, I did that and the signal doesn't change. Lets put this on hold for a week or two until I get a good digital scope. When you have a chance let me know what your opinion is on the below topic. That is this weekend project. I appreciate all your help.

https://www.badcaps.net/forum/showthread.php?t=68034

That is correct. I am wondering if the signal might not be making good contact; you might want to consider scraping off the "solder mask" in that area to reveal the copper so you can solder a wire to it, carefully.