motorola ts4d 7 inch

[timmy]

finishing up on another motorola table top tv with the 7jp4 crt and i have 3 crts 2 are bearly able to show a pic but they do and the brightness turned down the screen goes black and thats normal but i have the other crt and is brighter still not the best but the brightness turned down dont shut the screen down its as if the pot is bad or the b+ was taken away. my other set brightness shut this tube off but for some reason just this tube wont shut down but the other 2 will. any ideas why that is ?