is the servo broken?

hi i have a project with 2 servos , after a while of testing the servo start to go crazy , now with EVERY VALUE i write they go to 0 and continue to force making also noise and heat, i've tried also to use an example like sweep but nothing they always go to 0 and stay there , are they broken? how to fix this?

How are you powering them? Can the power supply deliver the current? Have you got any bulk decoupling capacitors on the supply?

i found a solution , if i detach a servo the other work , i think the batteries have not much charge for two servo, however servos are powered with 4 stilo AA batteries 1.2v 2500mah they worked great till now sorry for my bad english

tried with 4 other batteries but nothing :( i will charge this battery and retry