My CTC-16XL Project.

[Yamamaya42]

Originally Posted by Electronic M

Check the caps that filter the boost for shorts also check the line for shorts (such as tin whiskers on pots, insulation breakdown and such). Something caused that resistor to burn up like that.

Also, it may be wise to get a new boost diode. I've seen them fail more than once and what killed that resistor may have damaged the diode too...Radio Shack carries a 2A 1.5KV PIV diode that if you place 2 in series makes for a really rugged boost rect. Failing that similar specked diodes off the net will work.

My first roundy I came at the problem from the opposite direction. After fighting to get HV, and having sound, but no raster and chasing voltages I finally found my cooked boost rect...The hilarious part was that aside from no color and shrunken raster from dying caps the darn thing worked great on varic power up for a few secs before dying, and I never retested tube damper after power-up so after driving my self batty trying to get HV for a couple of months, and giving up I found the problem robbing the tube for another working set that had an intermittent damper arc.

a tin whisker like https://imgur.com/eUeytX9 that..
so i guess that pot is shot..