Tried to fix a 20 year old TV and made it worse

Last Sunday. Had a customer bring in an old CRT. Said it had vertical lines. I thought easy fix. Opened it up and accidentally touched the wrong cap with my probe. Big spark. Now it won't even turn on. Felt like an idiot. Customer was upset. Had to refund. Has anyone else made a simple job turn into a disaster like that?

3 comments

3 Comments

anthony_wells2mo ago

Bet that knocked out the vertical deflection IC too.

dylan_anderson2mo agoMost Upvoted

Wait hold on, you're assuming the vertical deflection IC got fried from the same surge. But what if it was a cold solder joint on the flyback transformer that finally let go first, and then that took the IC with it when it arced? I've seen that happen where the joint cracks from heat cycles over years, and when it finally snaps it sends a spike back through the whole deflection circuit. Did you check for any burn marks around the flyback pins?

rivera.keith1mo ago

That's a good thought, but I really think the surge came first in this case. The customer had a lightning strike close to the house and the set was plugged into a non-surge protected strip, so that's the more likely culprit. You'd be right about the cold joint causing issues eventually, but the timing here points way more to the power surge being the initial problem.