How to test tubes?

[CoG]

Hi all,

I'm just wondering if there's any way to test tubes for "working/not working" with a multimeter. I pulled a pair of EL84s out of my 20/20 because one side gonked, and I'd like to test them in a way that doesn't involve them potentially blowing a fuse in a real amp.

I could stick them in my Epi VJ one at a time, but it's not a great idea to stick a bad power tube in an SE amp, right...?

 

[stokes]

Its not a good idea to stick a bad power tube in any amp.What do you mean "one side gonked"?

 

[CoG]

One channel of the 20/20 stopped working completely. No degradation or anything, just turned it on and it didn't work. I checked the cables, they were fine, checked the sends from the preamp into another amp, they were fine. I tried replacing the two EL84s on that side, and it worked. So I am assuming one of the two tubes went.

The tubes were only about 4 months old but they probably had about 150 hours on them, so it's not unlikely that they could be dead, right?

I can always use single EL84s in my VJ, so I'm just wondering if there's a way to tell which of these two tubes is toast without endangering any amps.