Sanyo AVM-2554 Tuner Problems

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- francois.hugon
  
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posted
17 years ago

Sat, Dec 30, 2006 2:20 PM

Okay, this is me attempting to fix a TV when I probably should just go buy a new one...but I'm an engineer, which means I'm cheap and I think I can fix anything.

When I change the channel (with the remote or from the tv itself) the digital number telling me what channel I'm on changes. But the channel doesn't change (i.e. I'm still watching 5 even if I try to change to 6 even though the digital number says 6). Sometimes, it will eventually change itself, but not often. To me, this clearly points to the tuner. I've pulled out the main circuit to see if any solders looked bad that I could re-solder, but nothing stood out to me. Is this even worth attempting to fix, or should I just buy a new one?

Thanks, David

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- Meat Plow
  
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posted
17 years ago

Sat, Dec 30, 2006 2:58 PM

On Sat, 30 Dec 2006 06:20:53 -0800, francois.hugon Has Frothed:

Buy a new tuner.

--
Pierre Salinger Memorial Hook, Line & Sinker, June 2004

COOSN-266-06-25794

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- dkuhajda
  
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posted
17 years ago

Sat, Dec 30, 2006 5:47 PM

Couple of possibilities, it is an older set so I haven't seen one in a long time.

Open resistor on the 33V line. They use the regulated 120V source through a resistor to a zener and capacitor to supply the tuner with the 33V for the tuning voltage.

The tuner itself may have bad solder connections, especially to the ground structure. Be very careful to use proper grounding of your iron tip and yourself and care with the tight surface mount components if you get inside the tuner to examine and repair any connections.