while i was using the amp it quit and the display is blank and flashing light only.
You can try resetting the amp.
Beyond that there is little you can do. It could be a power supply fauly, or an issue with one of the PCA's that is preventing the power supply from starting up.
Either way, unless you are an electronic engineer with test equipment and a supply of spares you have little chance of fixing it. Unfortunately your only options are either ask Marshall to fix it or get another amp.