RCA KCS126A Resistor Melting Solder! - Videokarma.org TV - Video

Chris K · #1 02-16-2023, 07:17 PM

I can post the schematic if it would be helpful...It's in Sams Set 457 Folder 1. It's a 4.7k 1/2 watt resistor off the deflection yoke in series with the 2 big 2KV ceramic caps between the flyback and the yoke. If anyone has the Sams, it's resistor R69. I took a photo of the schematic attached. The TV works fine for about 5 minutes and the resistor gets so hot, it starts to melt the solder it's connected with. Any ideas what might be pulling so much current through this blazing resistor?

Thanks all!
Chris

Electronic M · #2 02-17-2023, 09:07 AM

My first guess is that the 2KV cap is going leaky or shorted as the set runs, effectively putting the resistor in parallel with the yoke.

Chris K · #3 02-17-2023, 09:35 AM

Quote:

Originally Posted by Electronic M

My first guess is that the 2KV cap is going leaky or shorted as the set runs, effectively putting the resistor in parallel with the yoke.

Thanks Tom, I'll look but the caps are new but maybe I got a value wrong. Your scenario certainly makes sense.

Chris

Chris K · #4 02-17-2023, 04:58 PM

Quote:

Originally Posted by Electronic M

My first guess is that the 2KV cap is going leaky or shorted as the set runs, effectively putting the resistor in parallel with the yoke.

Got it...It was the 1500pf 1.5kV cap. I had a 630v cap and blew it open when I went from 145v to 265v on the focus lead voltage. Working now. Thanks Tom.