LG 42LB5800-SB LED source LGP3942-14PL1, does not turn on the backligh
Hi Leo77, thanks for answering, the strips are tested, I have the problem in the BD9486F that does not oscillate, starts for 1 second and is cut, but does not turn on the backlight LEDs.
In leg 3 of OVP I have 1.19v and the protection works when it is greater than 3v.
My comment was based on what he said: "If I leave the source mounted it turns on, if I turn it to make some measurement it goes off." In addition "exciting the LED strip with a tester the image appears normal." I wonder if this tester has over-consumption protection as does the BD9486 ic. My idea is based on the experience of a TV, the LED strips were completely good, moreover I had another TV on hand and changed the strips to try, at times the TV was working and suddenly turned off, the problem it was in the unions between strips ...
If I raise the source and apply heat to the area of the BD9486, putting it in its place works without problems, just touched the plate stops working, I will try to check the clues and components to see if I find something and comment on it.
The strips are checked with 2 different commercial testers and another TV.
If, when handling the card, it stops working, it looks like physical damage but not electronic, visually check cut tracks, safed elements, cold welds, transformer pins related to the driver that are not sulfated. I had a tv with that problem, I don't remember if I gave it a solution, tomorrow I check between my notes to see if I wrote down something related. If the card goes into operation and does not handle it, how long does it last on?
Well, thanks for the contributions that Gilar and Leo77 gave me, I was able to find the problem. The fault consisted of the source connector with a false contact on the female connector card, the hole of the card was enlarged for some reason and I did not contact by suggestion of Leo77 I started to check the return of the 2 wires with a tester and I verified that he made contact with us, that is why when moving or touching the source plate it stopped working. When the LEDS chain was open, the BD9486 started by sending a pulse to the MOSFET gate and was cut. Thank you.