Had a chat with a retired TV repair guy last week that changed how I look at capacitor kits

He told me he always stocks 105C rated caps even for circuits that only need 85C, and after I switched my bench supply I've had way fewer callbacks on old CRT monitors - anyone else find that temperature rating makes that big a difference?

3 comments

3 Comments

brian_smith68d ago

Bet on 105C caps every time, learned that after recapping a Commodore monitor.

taylorellis8d ago

That retired guy knew his stuff. The higher temp rating gives you a lot more headroom for ripple current and general heat cycling, which those old CRT flyback circuits run hot. I started using 105C caps on all my monitor repairs a couple years back after too many 85C ones would drift out of spec in under a year. The extra few cents per cap is nothing compared to the headache of a callback.

emery_black8d ago

Yeah, that tracks with my experience too. Those 85C caps just don't hold up in tight spots near the flyback, especially if the board is cramped with no airflow. I switched to 105C rated ones for the main filter caps and the ones right off the HOT, and it cut down on those weird drift issues after maybe 8-10 months of daily use. Took a few repairs to figure out it wasn't just bad luck, it was the heat cooking the electrolyte.