Chosen Solution
Hello everyone. I’m new to this forum and looking for some help. I have an LG47LB5D that goes snowy after 30 minutes with a whineing noise, and then the picture comes back for a bit, but it keeps happening. The set gets very hot. I have replaced 7 caps that were bulging but that didn’t help. Any help would be fantastic. Update (08/14/2020) Thanks for the quick reply. I can’t tell exactly where the noise is coming from, but it does wind down in pitch before the picture comes back. As far the heat goes, it has always been a hot tv, so maybe it’s just me. I did clean up some brownish areas on some solder. I’m going to guess this would be flux? Here are the pictures from both boards.
Update (08/13/2020) I tried to touch up the solder joints as best I could. Let me know if these will work. Running out of time today. I will test it out later.
Hi @glenfricker , Don’t know the answer but a whining noise may be the SMPS power supply (presumably this is where the bulging capacitors were replaced) and the display going snowy would be the mainboard or perhaps the power supply to the mainboard. Check where the noise and the heat are coming from. If it is getting hot enough hopefully there may be some tell tale heat marks on the circuit boards. (check both sides) Post some close up images of the power board and the mainboard back here. (both sides). Here’s how to do this Adding images to an existing question Also this may be an option to consider as it should have the schematics for the power board at least. (I couldn’t find a free manual online, you may have better luck). Be safety aware when working in the back of a TV as there is exposed lethal AC voltage on the power board when the power is connected to the TV Update (08/14/2020) Hi @glenfricker , The only thing that I think that I can see but may be totally wrong is some suspicious looking solder joints on the power board. They look like dry joints but maybe it is just the picture or more likely my eyes. Try reworking them with a soldering iron and check. There may be others that I missed but if these don’t look quite right to you as well, check over the power board for any more. Here’s a composite of two images from the power board showing the zoomed in image, so you may have to look at the component designation to find the component.
(click on image to enlarge for better viewing)
