TV/VCR/Stereo Troubleshooting/Intermittent TV signal


I have an LG model 47LV5500 purchased in January this year in my bedroom, which is the coolest room in the house. The set operates OK most of the time, except when I plug in a space heater it blinks on and off every 20 seconds or so. The manual says when this happens it's because the TV is not plugged in properly, which isn't the case. Up to now I had been using an old space heater that dried out the air, and had no problem with the TV with this heater running on the same circuit. I recently purchased a new energy efficient space heater that doesn't dry out the air. When it is on, that's when the TV malfunctions no matter where in the house the heater is plugged. It doesn't affect my living room TV (Samsung), computer, or any other appliances to my knowledge. Do you think the heater is defective or is it the TV (which is OK otherwise)? Would plugging the heater into a surge protector solve this problem?

Only a wild guess could be offered on this unusual question.

It is likely, in my opinion, that either the voltages in your home outlets are a little low on voltage and/or the tv is sensitive to low voltage operation.  When the heater is plugged in it lowers the overall house voltage just enough to cause what you are getting.

Have you tried lugging the tv to a friend or neighbor house to see if the same result is obtained?  Another test might be to turn off some other electrical consuming appliances whilst the heater is plugged in.  This would let the voltage remain stronger.  However, electric heaters of any kind do draw lots of current from the house mains which might be at the cause.

Those are my thoughts.  Let me know if we need further discussion.  

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

©2016 All rights reserved.