Welcome back!
No worries, so you went through all the no sound steps?
Also,
Check the mains fuse, and replace if necessary. If it blows again, let me know.- Make sure you are using the top TO SPKR output, this must be used first.
If you have gone through the checklist and steps above, yes it’s time to suspect the tubes.
Do you have a spare set of tubes and fuses, see the information here on what you need and how to replace: