I'm back again. Sorry for just how disjointed my thread was last time.
The history of the TV is that I recieved it for free, and it wouldn't power on. When I would plug it in, there would be a click or two, and then nothing.
Shortly after getting it apart, while checking voltages, I bridged across a mosfet. I believe it's the one I circled in red:
(I'm an idiot apparently. There's no need to ask what I was thinking, or how it happened, or any of that. Just assume I've taken all the criticism needed.)
That blew the 6.3a 250v fuse on the bottom of the board.
After asking a bit here, and showing just how novice I am, I decided to get a different power board rather than try messing with things that are currently above my level. (I can solder in a new fuse, that's no problem, but since I didn't originally even know that it was a mosfet that I shorted, I figured the less actual SMD diagnosis I had to do the better.)
The "new" power board is a take off from a unit with a broken screen. It is used.
Once I installed it we were back to the original complaint, which was that the screen wouldn't power on, and the power board would click a time or two whenever plugged in, and once when unplugged.
I tested the voltages at the connector that leads to the main board, and the 3.5v and 24v were where they are supposed to be. I honestly don't remember then 12v.
Knowing that this model has a common issue with the BGA processor, I took a hairdryer to it for a few seconds to see if symptoms would change. Upon the next power up the clicks were still present, the LED board had a blue light that was blinking about every second, and the ethernet port on the main board had very dim lights on the green and yellow LEDS. I also observed that when reset, the capacitive touch points on the front would light up for a few seconds and then go off again. Also I could hear a high pitched ring from the area of the mainboard.
I gave the processor another heat, and then, nothing. Now no light on the LED board, no ethernet light, no clicks when plugged in or unplugged. Completely unresponsive.
I've checked all three fuses on the power board, and they're fine. The power source is still at 116v (tested where the cable connects to the board). The connector that runs from the PB to the MB reads as such (left to right):
0, 0, 0, 0, 0, 0, 3.3, 3.4, 0, 0, 0, 0
So now I no longer have 12v or 24v.
Is it possible that this could still be caused by a problem on the main board, or am I right to assume that I am right back to power board issues? What components would you recommend I check next?
So sorry for the long read.
The history of the TV is that I recieved it for free, and it wouldn't power on. When I would plug it in, there would be a click or two, and then nothing.
Shortly after getting it apart, while checking voltages, I bridged across a mosfet. I believe it's the one I circled in red:
(I'm an idiot apparently. There's no need to ask what I was thinking, or how it happened, or any of that. Just assume I've taken all the criticism needed.)
That blew the 6.3a 250v fuse on the bottom of the board.
After asking a bit here, and showing just how novice I am, I decided to get a different power board rather than try messing with things that are currently above my level. (I can solder in a new fuse, that's no problem, but since I didn't originally even know that it was a mosfet that I shorted, I figured the less actual SMD diagnosis I had to do the better.)
The "new" power board is a take off from a unit with a broken screen. It is used.
Once I installed it we were back to the original complaint, which was that the screen wouldn't power on, and the power board would click a time or two whenever plugged in, and once when unplugged.
I tested the voltages at the connector that leads to the main board, and the 3.5v and 24v were where they are supposed to be. I honestly don't remember then 12v.
Knowing that this model has a common issue with the BGA processor, I took a hairdryer to it for a few seconds to see if symptoms would change. Upon the next power up the clicks were still present, the LED board had a blue light that was blinking about every second, and the ethernet port on the main board had very dim lights on the green and yellow LEDS. I also observed that when reset, the capacitive touch points on the front would light up for a few seconds and then go off again. Also I could hear a high pitched ring from the area of the mainboard.
I gave the processor another heat, and then, nothing. Now no light on the LED board, no ethernet light, no clicks when plugged in or unplugged. Completely unresponsive.
I've checked all three fuses on the power board, and they're fine. The power source is still at 116v (tested where the cable connects to the board). The connector that runs from the PB to the MB reads as such (left to right):
0, 0, 0, 0, 0, 0, 3.3, 3.4, 0, 0, 0, 0
So now I no longer have 12v or 24v.
Is it possible that this could still be caused by a problem on the main board, or am I right to assume that I am right back to power board issues? What components would you recommend I check next?
So sorry for the long read.
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