Joined: 07 Jun 2016
|Posted: Tue Jun 07, 2016 2:28 pm Post subject: Samsung PN43E450 - Loud pop, now won't start up
This is my first post, and I was hoping to get some help with my TV. It is a Samsung PN43E450 and is about 3.5 years old. The other day, the set was on. I was in the room but not looking at it. I then heard a very loud POP and the set turned off and wouldn't turn back on. The standby light on the front of the set blinks intermittently, but will not stay on.
I have done a little with electronics and I love to tinker and fix things. I also cannot afford a new TV or even a big repair bill at the moment (I am a poor grad student). So, after checking all the obvious things (power cord, surge protector, etc.) I took the back cover off the TV, did some research, grabbed my multimeter, and have been trying to diagnose the problem myself. I was hoping that I would just be able to see some bad capacitors, but had no such luck. If I could figure out exactly what board is the problem, I would just order a new one from ShopJimmy.com and swap it in. If I could figure out exactly which component is the problem, I would get that and solder it in.
When all the boards are connected and I first apply power to the set, the voltage at both the Vs and Va test points spike my meter to OL and then fall back to zero. There is a green light on the logic board that blinks a few times every couple seconds when I first plug the TV in. When the light blinks, the voltage at these points spikes to OL and then falls to zero.
When I disconnect all the boards except the main board and the power supply board, Vs does some weird things. Once it charged quickly to around 400mV and then slowly fell. Once it slowly charged, then fell, then charged higher. Over a span of a couple minutes it got around 400mV and then I unplugged the set. With the boards disconnected Va seems to relatively consistently read -2.5mV.
Does this sound like the Power Supply board is the problem? If so, how can I confirm this? If not, how can I find out which of the other boards it is? I would prefer not to have to buy all the internal boards and just guess which it is. Also, ShopJimmy is out of the X/Y main board, so I'm hoping its not this one, haha.
Thanks for any help anyone can give me.