So, you have a turntable, speakers and a tube amp. No AM/FM?
The scraping sound could possibly be a worn idler wheel contacting the inside surface of the turntable platter and the motor pole.
I recall someone mentioning years ago that it is not good to run a tube amp without a load across the speaker terminals; possible damage to other components. There are "load" resistors, for lack of a better term, to put across the terminals to simulate a speaker hookup.
Check Record-changer's posts about turntable repairs. The man is awesome and his knowledge is immeasurable. If you go to the Archives, he is known as Larry Robinson. I wish I could have been an apprentice under him.
As far as a parts list, If you have removed the back, there may be a schematic pasted in the base of the unit or the back panel. They used to do that back in the old days. Even a speaker wiring diagram may be included. If you look at the amp itself, most of the components are labeled. You need to have a color chart to read the bands on the resistors to get their values. You could very easily get by without a schematic or service manual. They would really help when you need to do an tuner alignment for the radio section. In that instance, the alignment was set at the factory, and replacing the caps did the job without doing any adjustments.
With a unit that old, I would give it a whole set of fresh Electrolytic caps; probably wouldn't hurt to check resistors, too. Do a visual search for components that look dark/burnt from overheating. I've had a unit with caps popped open at both ends.
No wonder it didn't work.
If I find a bad component, I like to use a "ripple" effect to backtrack the audio chain to see if something else caused it to go bad. The only tools I have right now are a True RMS multi-meter and a Weller soldering station.
The meter has alot of features on it to test different semi-conductors, and it's gotten me through so far....would love to get more toys...LOL.
Semi-conductors are cheap, and you can always go online to check the NTE/ECG cross references or get the catalog/downloadable software. You can check out those weird numbers you may find on some parts. The most expensive repair would probably be a power or output transformer.
West-Tech(sp) services, in Florida(?), restores idler wheels, and a guy in Canada rebuilds phono cartridges. Radio Shack, Garage-a-Records and a host of others sell needles and some NOS cartridges. Sam's Photofacts, AG Tannenbaum, can't remember them all right now, have schematics and service manuals. Antique Radio Supply, just up the road in Phoenix, carries tubes, power/output transformers and all types of connections.
Just about anything you need can be had out there if you do a little research. There is hope for your unit and it can be restored. Sorry for all the rambling, just bored on this Thanksgiving day and family is back in Pennsylvania.
Sounds like you have a great unit and I hope you find everything you need to get it going again.
BobbyB
Tucson, Arizona
