HI all,
I have received some very helpful information from this forum in the past. As such, I wanted to give a short guide back on how I repaired my LE40B651 LCD. I still have an outstanding issues with a line of pixels on the LCD. I was also hoping that someone could offer some advice on this.
First off, I received the Samsung LE40B65 with the described issue of "Doesnt turn on".
When I took it home, I checked the fuse in the plug: There wasnt any. So I fitted a 5amp fuse. The TV still wouldnt turn on. I opened it up, and found that the two fuses on the H40F1_9HS bn44-00264c PSU were blown.
There was heavy scorching from sparking under one of the main input capacitors. I also noticed that two of the caps near the PSU output were swollen, but more on that issue later.
The fuses were rated at 3.15amp. I replaced them with two 3amp fuses. Leaving the PSU disconnected from the TV, I powered it up. Immediately the 3amp fuse near the power inlet blew. This indicated that there was a large short near the input of the PSU.
I removed power from the board, flipped over, and began investigating with my multimeter. With the diode test, I found that the two AC inputs to the TS6B05G bridge rectifier were shorted. This indicated that it was blown. Using a soldering iron, I swapped it with a bridge rectifier from a scrap PSU board.
I replaced the blown fuse and tried again. This time the TV powered up! However, straight away I noticed the noise: It gave off a loud high pitch squeal, similar to an old CRT, but louder. Using my ear and a toilet roll, the sound appeared to be coming from the main control board. My guess is that the swollen capacitors on the PSU werent stabilising the primary power rails badly. As a result, the secondly power supply circuits on the control board were struggling to correct their output, causing the noise.
More worrying was the image that appeared on the LCD panel. There were a number of vertical lines near the centre of the screen.
I figured that this was caused by a loose ribbon cable between the glass panel and the TCON board. I removed the panel and with the TV powered up, applied pressure with my thumb to the edge of the glass on the ribbon cable near the lines. I also tried to apply pressure on the IC near the lines, and the ribbon cable to the TCON board. I also applied pressure on the two main ICs on the TCON board (2009FA7M4C4LV0.9) Unfortunately the lines were unaffected. I checked all the connections, and also tried duster spray to cool the areas to no avail.
If its the panel thats gone, I guess the TV's goose is cooked and I will scrap it.
As such, I was wondering if someone more knowledgeable would know if this can be fixed? Could a replacement TCON board work? Or is she a goner?
I have received some very helpful information from this forum in the past. As such, I wanted to give a short guide back on how I repaired my LE40B651 LCD. I still have an outstanding issues with a line of pixels on the LCD. I was also hoping that someone could offer some advice on this.
First off, I received the Samsung LE40B65 with the described issue of "Doesnt turn on".
When I took it home, I checked the fuse in the plug: There wasnt any. So I fitted a 5amp fuse. The TV still wouldnt turn on. I opened it up, and found that the two fuses on the H40F1_9HS bn44-00264c PSU were blown.
There was heavy scorching from sparking under one of the main input capacitors. I also noticed that two of the caps near the PSU output were swollen, but more on that issue later.
The fuses were rated at 3.15amp. I replaced them with two 3amp fuses. Leaving the PSU disconnected from the TV, I powered it up. Immediately the 3amp fuse near the power inlet blew. This indicated that there was a large short near the input of the PSU.
I removed power from the board, flipped over, and began investigating with my multimeter. With the diode test, I found that the two AC inputs to the TS6B05G bridge rectifier were shorted. This indicated that it was blown. Using a soldering iron, I swapped it with a bridge rectifier from a scrap PSU board.
I replaced the blown fuse and tried again. This time the TV powered up! However, straight away I noticed the noise: It gave off a loud high pitch squeal, similar to an old CRT, but louder. Using my ear and a toilet roll, the sound appeared to be coming from the main control board. My guess is that the swollen capacitors on the PSU werent stabilising the primary power rails badly. As a result, the secondly power supply circuits on the control board were struggling to correct their output, causing the noise.
More worrying was the image that appeared on the LCD panel. There were a number of vertical lines near the centre of the screen.
I figured that this was caused by a loose ribbon cable between the glass panel and the TCON board. I removed the panel and with the TV powered up, applied pressure with my thumb to the edge of the glass on the ribbon cable near the lines. I also tried to apply pressure on the IC near the lines, and the ribbon cable to the TCON board. I also applied pressure on the two main ICs on the TCON board (2009FA7M4C4LV0.9) Unfortunately the lines were unaffected. I checked all the connections, and also tried duster spray to cool the areas to no avail.
If its the panel thats gone, I guess the TV's goose is cooked and I will scrap it.
As such, I was wondering if someone more knowledgeable would know if this can be fixed? Could a replacement TCON board work? Or is she a goner?
Attached Files
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