290 Problem

[WEGjr]

I recently got a Boogie 290 from ebay, and it is VERY noisey!
I get a lot of recurring static, sometimes right when I start
it up, and other times after playing for about 15 minutes.
I retubed it w/ a Eurotubes 290 retube kit, but it STILL continues
to do this, and it's really hacking me off!
The rest of my rig consists of a Triaxis, a G Major, a Lexicon
MPX1, and a DMC System Mix. I have a very clean rig- even
w/out the FX- just the Triaxis I get the same thing! I even took
the Triaxis out- so it's definitely the 290. Any idea what's going
on here?
I'm dreading having to take this into a repair shop, I JUST got
back the Triaxis after being w/out it for over a month!
Any ideas?

 

[disassembled]

I know you said you retubed with JJ's but did you replace the 3 12AX7's for the inputs and phase inverters? Are you using speaker cables? Did it make the noise with the old tubes? Maybe contact the original owner to see if they knew of the problem. Is the unit grounded? If it is beyond those you probably need to take it in for service. Good luck.