On Monday, February 11, 2019 at 10:54:45 AM UTC-5, wrote:
Circumstances: Dynaco SCA-35 that may be best described as "neglected" , as follows:

Filthy with greasy grit - what I would consider to be kitchen-type grease mixed with black grit similar to what landed on windowsills when I grew up in NYC, with regular dust co-mingled. To the point that individual components on the boards were very nearly indistinguishable.

Most of the controls sprayed with white lithium grease that had hardened to near-concrete status.

Most of the rotary controls frozen - hard. The exceptions being the rear hum-pots that had never been touched, and so remained operable.

Process: Rinse the entire shebang in WD-40, purchased in bulk and delivered via pressurized refillable aerosol can. Probably a pint used overall. Done over a trash-can with some kitty-litter on the bottom. This loosened the skunge. Rinse with CRC, over the same trash-can after 24 hours. This pretty much removed the _EXPOSED_ skunge on the controls, switches and boards. All of a sudden individual components became visible. Flushed the controls with WD and CRC - amazing the amount of waxy crap that came out.

Wipe down with lint-free cloth, stiff artists' oil brushes and high-proof isopropyl alcohol.

Apply lubricating cleaner to all rotary and sliding controls.
Apply Liquid Wrench to all shafts.
24 hours.
3 of 5 controls were free. Bass & Selector-switch still frozen, hard.
Apply Kroil. 12 hours. Re-apply Kroil.

All shafts are free.
I've got a jar of Kroil from my neighbor.
I read somewhere about ATF* plus acetone and
a third thing.. ethyl alcohol? that was 'better'
for unsticking nuts and bolts.
I never tried it.

George H.
*Automatic Transmission Fluid

More basic cleaning. Check _every_ connection with a dental pick. Tighten all tube bases. Apply power, no tubes. All good. 40 minutes, no unusual heat signatures.

Add tubes. Short inputs. As above, draws 85 watts, below nameplate of 110 watts. 1 hour, all voltages stable and correct.

Add speakers and signal - Voila! Sound, hum and buzz-free. All controls working properly.

Peter Wieck
Melrose Park, PA