Hey Guys - this one is the third one thru my shop that has same issues. I found and repaired this one so I will share to help someone else. It came in dead, no standyby light. When i pulled the back and checked voltage there was .08 on the standby and all the others. From previous experience with a different brand TV, I recognized the main board as one that shorts pulling the power down. I disconnected the ribbon cable to the main and all my voltages fell in perfect. Back when this TV came in I was still just swapping boards. The customer told me to just keep the TV he didn't want to spend any money on it.
Since then i decided to stop being a sissy and do the SMD repairs I was previously too intimidated to try. I thought how could anybody solder or replace a speck of pepper sized part.. LOL
I had a few and am still testing my waters so I put this one back on my bench. I knew from experience that for all the voltage rails to pull down to 0 it was MOST LIKELY a short to ground. Youtube can be a crock but it can also be a great educational tool. From watching many hours of electronics videos (like IpadRehab and Lewis Rossman many others) I had learned SMD caps usually short to ground when they fail. I ran with this premise so I found the shorted rails on the main and it was the 21v and the 13v... I downloaded the service manual with schematic. I followed the path to the closest IC on the schematic. The mistake I made was to follow the 13v path first. I should have followed the 21v path. I would have found my short quicker. NOTE.. had I looked more carefully at the schematic I would have seen the 21v was being broken down into the lower voltages.
I started removing the caps in the path until I found the short. 9 in total. Only 1 was shorted and it WAS on the 21v rail next to the audio chip. Likely reason they failed was it appears the factory reduced the number of filter caps to save money. (you can see where the schematic was engineered for more) Anyway it is now fixed and all I used was 9 new SMD caps 4 -.1uf and 5 - 4.7uf. (I didn't put any i removed back on).
Online that board sells for from $30 to $60. I am awakened to the fact that if I can get faster at board level diagnosis and repairs I can make more money WHILE I save my customers money. Win win... so I shared this small victory to help another guy like me......
Since then i decided to stop being a sissy and do the SMD repairs I was previously too intimidated to try. I thought how could anybody solder or replace a speck of pepper sized part.. LOL
I had a few and am still testing my waters so I put this one back on my bench. I knew from experience that for all the voltage rails to pull down to 0 it was MOST LIKELY a short to ground. Youtube can be a crock but it can also be a great educational tool. From watching many hours of electronics videos (like IpadRehab and Lewis Rossman many others) I had learned SMD caps usually short to ground when they fail. I ran with this premise so I found the shorted rails on the main and it was the 21v and the 13v... I downloaded the service manual with schematic. I followed the path to the closest IC on the schematic. The mistake I made was to follow the 13v path first. I should have followed the 21v path. I would have found my short quicker. NOTE.. had I looked more carefully at the schematic I would have seen the 21v was being broken down into the lower voltages.
I started removing the caps in the path until I found the short. 9 in total. Only 1 was shorted and it WAS on the 21v rail next to the audio chip. Likely reason they failed was it appears the factory reduced the number of filter caps to save money. (you can see where the schematic was engineered for more) Anyway it is now fixed and all I used was 9 new SMD caps 4 -.1uf and 5 - 4.7uf. (I didn't put any i removed back on).
Online that board sells for from $30 to $60. I am awakened to the fact that if I can get faster at board level diagnosis and repairs I can make more money WHILE I save my customers money. Win win... so I shared this small victory to help another guy like me......
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