Not sure about Miller "Repair" manuals but you can get owners manuals for most of there machines from their website. I'd be very surprised if they do a repair manual.
Yeah they have factory repair manuals they probably don't want anyone outside of factory authorized service centers to have them. Mere owners of these machines are simply outside of the "priesthood of the know".
Huh!?, That's interesting I've searched their site and cant find anything on factory repair manuals. Did you find it on their site or just phoned them?
That's because you're not an authorized dealer. On their home page, top left, you'll see "partner login". That's where we get to go that the general public can't.
For that age unit Miller Customer Service might even email you the .pdf version for free if you ask nicely.
They do however refrain from giving out service manuals for HF equipped units due to the higher voltages associated with them but are still very willing to help troubleshoot with you over the phone. (929) 734-9821
Miller has changed the rules on tech manuals.
If they find anyone giving out tech manuals they can take away your access to them.
Not saying this is absolute in every single case but possible.
They say knowledge is power but in your case your just a selfish idiot you should care about the laws and help your fellow welding inthuisiest and not the greedy corp. To hold tight information to which everybody should have access to they've already sold you the machine why not the knowledge. Ps your just a scared dick grow up and allow others to grow