Desktop monitors, tried 3, wont turn on after computer froze.

Desktop monitors, tried 3, wont turn on after computer froze.

Weird sound then short electrical hum. Screen froze. Manual computer restart. Can hear it but monitor is black. Monitor check on another computer. Monitor is fine. Checked cables. Blew out dust. Tried different graphics card and nothing. Monitors - tried 3- still wont come on. Which hardware part could have blown?