Greetings - first post. I'm awed that a forum like this exists. It's a dream come true. I'm not even kidding.
I've got a 13 year-old Sharp LC52LE700UN television that's developed a problem of powering itself off after 30-45 seconds. If I pull the mains cord and reconnect, it will come back on right away without so much as a button push...then turn off after 30-45 seconds.
Service manual S37X3LC46E77U is attached to this post, as well as a front and a back picture of the RDENCA336WJQZ DPS-286AP power supply taken after completing my work.
Each time that the TV's power supply would shut itself off, the power LED and OPC LED would flash twice, together, about 1/4-second per flash, then the OPC would flash a third time for about 1/4 second, then there would be a 1/4-second pause, and the sequence would repeat. The service manual said this error was "DET_6V (56pin) error (L). D5V or A5V is not applied. If error is detected during operation, error standby is activated by polling."
There don't appear to be any visibly damaged components on the power supply. After reading here that 5V standby voltages could be a problem, I ordered an sj-RDENCA336WJQZ repair kit from shopjimmy.com.
For my gear and skills, I have a 50W soldering station, a small desoldering iron, and a Fluke 113. I have some experience with board-level work, mostly ripping-and-replacing through-hole components on audio equipment. I also have very little circuit design experience which applies here.
I replaced IC7905 TNY264PN with a socket, then plugged in the new bagged part from the sj kit, which is a matching TNY264PN.
IC7905 is the only part of the sj kit that is a direct match for the original components.
D7908 came out, it is a 5383B, and it passed the diode check off the board. It was replaced with the new bagged part from the sj kit, which is a 5358B.
R7914 tested off the board at 2.3 ohms. Even though it looked different, I replaced it with the bagged part from the sj kit, which is a 5.6 ohm 1/2-watt sized resistor, colored grey with green-blue-gold-gold stripes.
R7918 tested off the board at 2.3 ohms. It is a 1/2-watt sized resistor, colored tan with red-red-gold-gold-silver stripes. I replaced it with the bagged part from the sj kit, which is a 0.22 ohm 1/2-watt sized resistor, colored light blue with black-red-red-silver-gold stripes.
After completing that work, the power supply does not power on when the mains cord is plugged in.
After reading some more, I lifted one leg of D7905 just to see if it would help. I didn't make a difference.
I'm not too surprised, because I really don't know what I'm doing. This whole thing is an excercise in using a minimal skill set to grasp at straws and save a television from the dumpster.
Having burnt enough time on it, I ordered a matching used power supply from eBay. The seller claims that it came from a working TV, and he's got respectable feedback so I feel comfortable with the purchase. He also accepts returns for 30 days. My plan was to keep the eBay power supply if it brought the TV back to life, and return it if it didn't. As it stands now, it's going back. I prefer to fix the original power supply if that's at all possible.
Sadly, with the eBay power supply installed, the set powers on like before, but it still shuts off like before. Except now when it shuts off, the power LED and the OPC LED will flash twice, about 1/4 second per flash, then pause for about half a second, and repeat. The service manual says that it is a "DET_D3V3 (59pin) error (L). D3.3V is not applied. If error is detected during operation, error standby is activated by polling."
I bet I'd end up back where I started if I returned the original components to the original board, and tacked D7905 back down. The TNY264PN didn't survive being desoldered, but the original D7908, R7914, and R7918 are all OK. But then I think about that eBay power supply, with its different error code.
So at the end of all this typing and reading and thinking, I've got two power supplies, each showing a different error code, and a Sharp LC52LE700UN television that won't stay powered on for more than 30-45 seconds at a time, and I have to disconnect the mains cord before each attempt.
What's likely to be the problem here?
Thank you so much --
I've got a 13 year-old Sharp LC52LE700UN television that's developed a problem of powering itself off after 30-45 seconds. If I pull the mains cord and reconnect, it will come back on right away without so much as a button push...then turn off after 30-45 seconds.
Service manual S37X3LC46E77U is attached to this post, as well as a front and a back picture of the RDENCA336WJQZ DPS-286AP power supply taken after completing my work.
Each time that the TV's power supply would shut itself off, the power LED and OPC LED would flash twice, together, about 1/4-second per flash, then the OPC would flash a third time for about 1/4 second, then there would be a 1/4-second pause, and the sequence would repeat. The service manual said this error was "DET_6V (56pin) error (L). D5V or A5V is not applied. If error is detected during operation, error standby is activated by polling."
There don't appear to be any visibly damaged components on the power supply. After reading here that 5V standby voltages could be a problem, I ordered an sj-RDENCA336WJQZ repair kit from shopjimmy.com.
For my gear and skills, I have a 50W soldering station, a small desoldering iron, and a Fluke 113. I have some experience with board-level work, mostly ripping-and-replacing through-hole components on audio equipment. I also have very little circuit design experience which applies here.
I replaced IC7905 TNY264PN with a socket, then plugged in the new bagged part from the sj kit, which is a matching TNY264PN.
IC7905 is the only part of the sj kit that is a direct match for the original components.
D7908 came out, it is a 5383B, and it passed the diode check off the board. It was replaced with the new bagged part from the sj kit, which is a 5358B.
R7914 tested off the board at 2.3 ohms. Even though it looked different, I replaced it with the bagged part from the sj kit, which is a 5.6 ohm 1/2-watt sized resistor, colored grey with green-blue-gold-gold stripes.
R7918 tested off the board at 2.3 ohms. It is a 1/2-watt sized resistor, colored tan with red-red-gold-gold-silver stripes. I replaced it with the bagged part from the sj kit, which is a 0.22 ohm 1/2-watt sized resistor, colored light blue with black-red-red-silver-gold stripes.
After completing that work, the power supply does not power on when the mains cord is plugged in.
After reading some more, I lifted one leg of D7905 just to see if it would help. I didn't make a difference.
I'm not too surprised, because I really don't know what I'm doing. This whole thing is an excercise in using a minimal skill set to grasp at straws and save a television from the dumpster.
Having burnt enough time on it, I ordered a matching used power supply from eBay. The seller claims that it came from a working TV, and he's got respectable feedback so I feel comfortable with the purchase. He also accepts returns for 30 days. My plan was to keep the eBay power supply if it brought the TV back to life, and return it if it didn't. As it stands now, it's going back. I prefer to fix the original power supply if that's at all possible.
Sadly, with the eBay power supply installed, the set powers on like before, but it still shuts off like before. Except now when it shuts off, the power LED and the OPC LED will flash twice, about 1/4 second per flash, then pause for about half a second, and repeat. The service manual says that it is a "DET_D3V3 (59pin) error (L). D3.3V is not applied. If error is detected during operation, error standby is activated by polling."
I bet I'd end up back where I started if I returned the original components to the original board, and tacked D7905 back down. The TNY264PN didn't survive being desoldered, but the original D7908, R7914, and R7918 are all OK. But then I think about that eBay power supply, with its different error code.
So at the end of all this typing and reading and thinking, I've got two power supplies, each showing a different error code, and a Sharp LC52LE700UN television that won't stay powered on for more than 30-45 seconds at a time, and I have to disconnect the mains cord before each attempt.
What's likely to be the problem here?
Thank you so much --
Attached Files
Comment