Rectifier or power tube?

A couple of weeks ago I started to have an issue with on of my VTA ST70's on power up.  Occasionally I'd get static on the right side, and I noticed that one of the power tubes was not lighting up.  OK I know all of you are saying well replace that power tube, which is exactly what I should have done.  I'm not sure if it's the experimenter in me or the cheapskate in me but I could coach that tube into firing and all would be fine.

Last night I powered up and the same filament issue happened but with a new twist.  My rectifier put on a light show!  The fuse blew and I successfully took out a power tube and a rectifier.  After replacing both my amp is running fine.  

Lesson learned.

Kaner

just double check the pins in your tube sockets, make sure they are all nice and tight and clean!
How old is the ST70?

Good advice, although I knew it was the power tube because when I moved it around the problem followed the tube. The chassis is from the 60's but all else is about 3 years old.