From: ohg...@gmail.com   
      
   On Monday, July 25, 2022 at 2:07:23 PM UTC-4, John Robertson wrote:   
      
   > >   
   > One of my employees brought in a Samsung 55" UN55JU7100 that has a    
   > shorted primary side of the switching supply. Hard short at the output    
   > of the first bridge rectifier. Noticed a few small value caps that are    
   > slightly bulging - is there anything else to check/replace on this    
   > series other than the shorted MOSFets and suspect caps?    
   >    
   > I'm going to suggest he add a small fan to the backside of the TV to get    
   > longer life...    
   >   
      
   No, you'll be good to go.  Just change the shorted MosFets and the caps, and   
   it should fly.  If you're very unlucky, the gate driver IC might have failed   
   but usually the fuse will blow quick enough.  If the customer changed or   
   jumped the fuse, the gate    
   driver IC will most likely fail on AC plug in.     
      
   You don't need a fan, but they way to extend the life of these is to lower the   
   back light setting.  Any TV I repair automatically gets a small mod to reduce   
   the back light current regardless of where the customer sets the adjustment in   
   the picture menu.     
   Most LED TVs use a fixed LED voltage on the high side of the array and a   
   MosFet on the low side which controls the current.  I raise the value of the   
   MosFet Source resistor (senses current) to fool the feedback.     
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)