Re: Samsung PN43E450A1F Troubleshooting

Okay, here are some pictures of the different boards. I also disconnected all the boards and tested the resistances in isolation. When I did this, the only test point that showed a 1-2 ohm resistance was SVT_VS on the X/Y main board (0784). This seems to isolate the problem to this board, correct?

Do you guys think it would be okay to replace this whole board with one from ShopJimmy, or would I need to replace the X and Y buffers too? Alternatively, would there be any way to isolate exactly which component on this board failed?...

Re: Samsung PN43E450A1F Troubleshooting

Thanks, Dick. The resistances I got doing what you suggested are as follows.

Vs - moved around a bit the few times I would check it, but stayed around 1-2Ω
Va - always 17.46 kΩ
SVT_Vscan on the X/Y Main - Would start OL then fall gradually to around 100 kΩ
SVT_XOut on the X Buffer - Would start OL then fall gradually to around 100 kΩ
SVT_VS on the X Buffer - 1-2Ω
SVT_VS on the X/Y Main - 1-2Ω
SVT_VE on the X/Y Main - Would start OL then fall gradually to around 100 kΩ

Re: Samsung PN43E450A1F Troubleshooting

Thanks for the reply TW. My meter is autoranging with a max of 600V. So, OL should mean well higher than what it is supposed to be, which is 209V.

Could you please talk me through how to check for shorts and resistance on the Vs lines? If its not the Power board, my next suspicion would be the X/Y main board.

Re: Samsung PN43E450A1F Troubleshooting

Clarification of my previous post. When only the Power supply and main boards were plugged in, the voltage on Vs steadily climbed to 400mV before I unplugged it. I checked this again today, however, and it did something different. This time the voltage at Vs quickly spiked to 400mV and then slowly discharged back down to almost zero. When all boards are connected the voltage at Vs and Va spike to OL when I first give power to the tv and then fall back down. This seems like the problem is with the power supply board to me. What can I check...

Re: Samsung PN43E450A1F Troubleshooting

Thanks for all the help. So, I checked the VS and the VA voltages at the test points with all the boards plugged in. When I do this, VS spikes my meter to OL and then dies back to zero. I next unplugged the X and Y boards from the Power supply and tested VS and VA again. Va read -2.5mV and stayed constant. Vs is supposed to be 209V. When I put power to the TV, the voltage on this test point was low, but kept climbing steadily. It would go up, and then go down a few volts, and then go higher than before. After a minute or two of the TV being...

Re: Samsung PN43E450A1F Troubleshooting

I unplugged everything from the main and power supply boards and the tv still won't power on at all. Wouldn't this rule out all the x and y boards as being the problem? Also, I've seen the green light on the logic board, but it doesn't stay on or blink rhythmically.

Yesterday, my TV was on. I was not watching it and had my back turned when I heard a loud POP. I turned around and my TV was off and would not turn back on again with the remote or the power button. I first checked my surge protector and cords, and I did not find any problems. All of my other components worked fine. Also, the standby light on the TV blinks intermittently. So, I know it is getting some power.

I next took the back off the TV. I hoped I would be able to find a blown capacitor or something visually the problem, but everything internally looks fine. Following this visual...

Re: New Members - please post your introductions here

Greetings!

My name is Luke, and I live in St. Louis. I like to fix things and occasionally that sends me into the realm of electronics. I've worked on some computers and some old cameras. Recently, my TV stopped working. So, I am here to see if I can fix it without spending an arm and a leg.