JTM Build Blowing HT Fuse when Power Tubes installed

[RPercival]

I just finished wiring up my JTM45 last night and everything checked out well until I put in the power tubes and turned the standby switch to run. With the tubes out everything is fine but with tubes in the fuse blows. I've looked over everything and it all looks correct to me. I also tried another set of tubes to eliminate bad tubes from the equation. Has anyone had this issue or any experience with it? I'm kinda stumped and could use a nudge in the right direction. Thanks all.