原创 Repairing the TV lightning killed

My grandparents' TV went dead. My dad, a radio and TV repair person, took a quick look and thought the damage was caused by a line spike, maybe from lightning. The tuner didn't appear to be damaged. He didn't have the time to take on this repair, although more likely he thought it was a lost cause.

He issued me a challenge to fix it. Wait a minute, pop! You want me to rebuild a TV that was possibly hit by lightning? Cool! I knew it wouldn't be pretty, but I accepted. My dad was correct. Only the IF section was toast. Really, fried remains of resistors, coils, and caps burnt to a crisp.

It looked like someone had taken a torch to the IF section. I got out the SAMS service manual. I can't remember the exact make. The TV may have been a Philco, RCA, or Magnavox. I started the rebuild with the easy stuff first, replacing the tubes, resistors, and caps. I had to match up the resistor values from the schematic, since the colour codes were different shades of burnt umber... pun intended.

The IF coils were my biggest worry. Luckily the coils had only minor smoke damage with a couple of open windings. I carefully cleaned up the coil forms and re-wound the open ones with the same size copper wire. Six weeks had elapsed since I started, and finally the work was done.

It was time for the smoke test. It was the most nerve-wracking moment: Would my Frankenstein TV come to life or... just smoke? I carefully flipped on the switch, standing well back, just in case. It was ALIVE! NO smoke! It really worked. The picture and sound were both functional. Actually, very functional indeed considering what I had done to the IF section. On Thanksgiving day my grandparents had their TV back.

Note: To protect the innocent the exact details and names have been changed. Plus this happened about 40 years ago, when I was 15 years old and just starting 10th grade!

Dave Grindel submitted this article as part of Frankenstein's Fix, a design contest hosted by EE Times (US).