The activation of only the card "Cyber Summon Blaster" can be performed at any time, except during the Damage Step.[1]
The effect "Each time a Machine-Type monster(s) is Special Summoned: Inflict 300 damage to your opponent" makes a Chain Link. (It does not target. The effect activates each time a Machine-Type monster is successfully Special Summoned in either player's turn.)[1]
If "Cyber Summon Blaster" is already face-up, the effect "Each time a Machine-Type monster(s) is Special Summoned: Inflict 300 damage to your opponent" will activate even during the Damage Step.[1]
The effect "Each time a Machine-Type monster(s) is Special Summoned: Inflict 300 damage to your opponent" cannot be activated in the same Chain Link as the card "Cyber Summon Blaster".[1]