how can i fix my proline and mogen flat screens no picture screen goes blan?

Are they actualy connected to any signal source?
If there is no signal, a brief "No signal" message is displayed, then, the screen goes into sleep mode and goes blank.

Check all cablings. The cables need to be connected to the monitor and a signal source.

A cable between the two monitors won't do, a monitor is not a signal source and probably can't be used as a relay.

Electro
July 2013