zacmackra:
i tried it hard with the shopkeeper to know whether the capacitor is y rated but it seems like he just does not know anything about his products. anyways i brought this 100nf 400v capacitor with no polarity marking, will this work?
image given
model no -100k400
Looks like polyester.
It's unlikely to burn/explode but 600V would be a better choice if he has them.