TV/VCR/Stereo Troubleshooting/tv won't power up


I have 2007 Sylvania 42" LCD HDTV model: LC420SS8.  When it's plugged-in, it makes a buzzing/humming sound.  When I push the power button, the sound changes a little for a second and the green lite flashes, but goes out and red stand-by lite comes back on.  What could be wrong and is it fixable?

I'm guessing you have a bad power supply and the power supply board may need to be replaced.  There is no way to know for sure without either just replacing it or have a technician test the set for troubles.

Also, on this model I found some comments online that claimed the power transformer was causing the buzzing sound and that it could be eliminated or reduced by opening up the back cover (disconnect the power cord of course!) and placing an empty toilet paper roll in between the transformer and chassis to stop the buzzing vibration.  You must investigate that aspect to see if it has merit for your set.

That's the best I can offer for now.  Let me know if you have further questions.  

TV/VCR/Stereo Troubleshooting

All Answers

Answers by Expert:

Ask Experts




Consumer Electronics of all kinds. Audio, esoteric audio systems and components, video, tv. Digital equipment for consumer use. Ham radio and automotive electronics. Note: I give advice on tv repair based on general consumer electronics engineering experience but I am not engaged in actual repair of sets. MAKE SURE YOU GIVE THE MAKE AND MODEL NUMBER AND AGE OF THE SET. BE SURE TO CHECK YOUR EMAIL FOR THE RETURN ANSWER DURING THE NEXT 24 HOURS AS I TRY TO REPLY TO ALL QUESTIONS WITHIN THE SAME DAY IF NOT THE SAME HOUR.


Electrical Engineering; recording, broadcasting, design, international standards, tv and radio theory and practice.

FELLOW of AES (Audio Engineering Society)
Senior Life Member of IEEE (Institute of Electronic and Electrical Engineers)
International Consulting Organization

IEEE Spectrum
Various Consumer Electronic publications


Awards and Honors
Famous Engineer for Digital Audio

©2017 All rights reserved.