I have an old Sharp LC-42SB45U set that went out in late April of 2019. In reading other threads here on the forum about this specific set, I decided to go ahead and replace a majority of the capacitors on both the PSU and Control boards. When plugged in, the red standby light does not come on, however, the set will power on randomly after a few hours, and stay on until it times out if not powered down intentionally.
Following the time out, the set will not power back on unless it is unplugged for a few hours, then plugged back up, only powering on when it gets ready, and not responding to the power button. If the unit is allowed to time out, then the red standby light comes on, however, if it is powered down using the power button on the side or on the remote, the light goes out completely with no further response from the set. Seems as if it has to go through some sort of reset period here.
Right now, the red standby light is on because the unit powered on at about 2 am this morning, 7.4.19, and was allowed to time out overnight, but if I were to go and press the power button, the standby light would go off without the unit powering up. However, I have noticed that when I attempt to power the unit up with a red standby light, the capacitors are warm to the touch after a few minutes as if the set wants to power on, but nothing happens.
I replaced all but the large 450V capacitor on the PSU board (excluding the turquoise ones) and all but two of the green 470uf 16v CapXon capacitors on the control board (again, excluding the turquoise components). Are the turquoise components capacitors as well? Neither of the capacitors I replaced was bulged or leaking, although the ones removed were tested using the continuity function on a multimeter and a few of them didn't conduct. The two remaining green CapXon caps are warm when the power button is pressed following a red standby light, along with the majority of the ones I replaced, so it seems as if they still conduct fine.
Attached are pictures of both boards and a picture of the screen when the unit does decide to power up. That photo does the screen no justice, but the picture is much clearer after replacing the capacitors I did.
Since I have determined that the set still works and displays a nice picture, I would like to see if I can fix whatever the issue may be and squeeze as many more hours out of it as possible. I'm probably looking over something simple.
Referenced threads:
https://www.badcaps.net/forum/showthread.php?t=18894
https://www.badcaps.net/forum/showthread.php?t=44996
Following the time out, the set will not power back on unless it is unplugged for a few hours, then plugged back up, only powering on when it gets ready, and not responding to the power button. If the unit is allowed to time out, then the red standby light comes on, however, if it is powered down using the power button on the side or on the remote, the light goes out completely with no further response from the set. Seems as if it has to go through some sort of reset period here.
Right now, the red standby light is on because the unit powered on at about 2 am this morning, 7.4.19, and was allowed to time out overnight, but if I were to go and press the power button, the standby light would go off without the unit powering up. However, I have noticed that when I attempt to power the unit up with a red standby light, the capacitors are warm to the touch after a few minutes as if the set wants to power on, but nothing happens.
I replaced all but the large 450V capacitor on the PSU board (excluding the turquoise ones) and all but two of the green 470uf 16v CapXon capacitors on the control board (again, excluding the turquoise components). Are the turquoise components capacitors as well? Neither of the capacitors I replaced was bulged or leaking, although the ones removed were tested using the continuity function on a multimeter and a few of them didn't conduct. The two remaining green CapXon caps are warm when the power button is pressed following a red standby light, along with the majority of the ones I replaced, so it seems as if they still conduct fine.
Attached are pictures of both boards and a picture of the screen when the unit does decide to power up. That photo does the screen no justice, but the picture is much clearer after replacing the capacitors I did.
Since I have determined that the set still works and displays a nice picture, I would like to see if I can fix whatever the issue may be and squeeze as many more hours out of it as possible. I'm probably looking over something simple.
Referenced threads:
https://www.badcaps.net/forum/showthread.php?t=18894
https://www.badcaps.net/forum/showthread.php?t=44996
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