Hey there, I've got a few queries and just wanted to hear some of you folk's opinions.

First problem:

Okay, my Mesa F-50 Head is really weird. I've got it recently but ever since I've got it, everytime I turn it off, I need to change the fuse because it breaks. So I place one in and everything is fine and dandy. After playing, I turn it off. If I wanna play again, I will turn it on, but then the fuse breaks, then I got to replace it; and thus this cycle begins to form. I've done this 3 times and as you can imagine, I'm fed up.

Also, there is no reverb. I tried turning the knobs, using the footswitch but absolutely no change, which is problematic because I would like to use that particular function very much.

I turn the thing off and on properly. I made sure that it was connected to speaker, so I don't understand. I tried it before I bought it and everything was okay when I was there. What is the problem? Do I need new tubes?

Second problem:

If I do have to get new tubes, I'll be looking to order some online off eurotubes.com. I'll probably get the appropriate mesa f series tube package. If I'm not mistaken, I'm pretty sure the mesa head doesn't have a bias pot (?) so its fixed bias. Would just be simply plug the new tubes in and play?

Third problem:

Not a really a problem, but just want to hear some opinions At the moment, I have the mesa head and a squire strat. I was planning to upgrade my guitar to an epiphone les paul (or maybe prs se if I can find a nice deal lol) but then I read that replacing stock tubes with some other tubes improve the tone a lot.

I have a budget of £250 max, so if I get the tubes, I'll get some pedals that I've been wanting for a while I'm just looking at what can improve my tone the most. If you want to know, I'm looking to play stuff like creed, alter bridge and maybe a bit of post-hardcore.

Thanks for the help in advance.

P.S My god, sorry about the wall of text!
replace your tubes do it now before you f up your amp.
Jumping on dat gear sig train.
PRS Hollowbody II / BKP Warpigs
Strandberg OS6T / BKP Aftermath
Strandberg OS7 / Lace Poopsticks
Skervesen Raptor 7FF / BKP Warpigs
Skervesen Raptor 6 NTB / BKP Juggernauts
Hapas Sludge 7 FF / Hapas Leviathan
Anderson Baritom / Motorcity Nuke BKP Sinner Anderson H2+
Warmoth Baritone / BKP Piledriver
Ibanez Rg2120x / BKP Nailbomb

Blackstar ID:Core Beam
Well okay, I kinda lied because I've done the fuse replace more than 3 times. Last time I put more fuses in, it broke. Then I tried again, it broke. Then I just gave up because of fustration/no more fuses.

I wish I asked ealier :/ What's the worst could happen per se?
Dude stop what you are doing and take it to a tech before it gets really costly. Just replacing the tubes might not fix the problem.
Yeah, probably be good idea. I guess I just thought I could take matters in my hand :/ Damn snow and exams means I probably won't get to get one in another two weeks probably