Audio Research d79 blows plate fuse

My audio research d79 blew the plate fuse when i turned it on this morning.Change fuse and it blew also.Any help would be greatly appreciated.
Hopefully; it's simply a tube. Another possibility is a
leaky or shorted coupling capacitor(especially based on the
age of the amp). If so; it will either be the 2uF or
.22uF(bypass)/600V, mylars.
Thanks for the response.I'm gonna get a new set of tubes and hopefully that is all it is.
Thanks for your response.I'm gonna get a new set of tubes and hopefully that will take care of the problem.
Not so fast. You may have damaged a resistor near the problem output tube if it is indeed an output tube failure. If you replace the output tube and a resistor(s) failed, the tube may not light or the new tube may be damaged. You should have the amp looked at before installing new tubes.
Thanks i am taking it to get it looked at this weekend.Hopefully it will be a cheap fix.Also will be getting a quote on a complete rebuild.
Agree with Hifigeek1 - Output tube may have shorted, taking out a resistor. Needs to be checked by a qualified tech. Doubt just putting in new tubes will solve the problem.
Pka, do you intend to get a quote from ARC re the rebuild. Just curious how much they would charge.
I use Mufich Audio in Mckinney TX.He has done a lot of work for me.He is a excellent Technician.I will let you know how much the rebuild quote is.