、。
If I fail, I'll probably try again.
Literal
By-chance fail-[conditional-ば], I [topic-は] once-more try [probably-だろう].
やってみる is the set pattern やる + ~てみる ('try doing'). The ~てみる auxiliary means 'do X and see (what happens),' 'try X.' It converts any action verb into an exploratory attempt.