Hartke HA5500 tube preamp no output
 

As the title says, the Hartke HA5500s tube preamp has no output signal. I was playing and it was working just dandy, then when i adjusted it later on i heard it all of a sudden had no output signal.
Its not really a big deal as i prefer the SS preamp, but i did enjoy mixing the SS with the Tube (while it lasted).
This amp isnt new, i started using it today but i bought it off a guy who owned it for 5 years.
If anyone has any idea what the problem might be help is much appreciated.

Probably the pre-amp tube, easy to open up and replace on those!

after googling the life expectancy of tubes, it seems very probable that the tube has had a long full life and died. So ill get a replacement tube as its only $30 for a decent one. I remember the tube preamp sounding incredibly muddy anyway so i might as well even if its not dead.
Thanks

I had a HA3500 as my first "real" amp, the tube went all horrible sounding after about 4 years!

I replaced the tube and there is still no output :( a few people with HA3500s are getting burnt out resistors and such, might be the cause?
wonder how much repair shops charge for these kinds of jobs...