I use my PS2 as an amp, connected to my Firehawk pedal and using the speaker of my dlx reverb (I don’t run it through the amp - I just use its speaker.)
A few seconds after turning on the ps2, loud crackling noises come from the speaker, eventually leading to a blown internal fuse.
I have:
replaced the 6l6 with another set → no difference
Exchanged the 12ax7 with a other one → no difference
Unplugged the input cable while it crackled → crackling continued
There is no smoke or smell or visible signs of burned components.
Typically if the Power Station fuses are blowing and you have already swapped the tubes with known good ones, there is something wrong that will need a service.
Where are you located and where and when did you purchase the unit from?