My amp died please help
So I've known for a while I need to change out my tubes but I haven't had the cash so I've been putting it off. Yesterday as I was playing the amp just died the volume faded and the jewel light went out and both channels make no sound. The amp is a fender prosonic so it has a rectifier and power tubes. I'm just wondering which tubes caused it to die. Is there any easy way to tell if it's the preamp, power or rectifier?