The manual for the CR-440 is too large to upload but again it is downloadable at hifiengine.com(must sign up) or contact me at r_brumett@yahoo.com and I will upload it to you.
You have narrowed the problem too the noneletrolytic caps, variable resistor pot. it is one or more of those items. I would check out of circuit (caps one leg and pots removed).
In 1968 after the USAF and while finishing college I was able to get my second system(sold first). It was AR 2axs, AR Amp, AR XA with Shure v15(3) and a Fischer(?) AM/FM Tuner. It was great and very impressive!
Just received a new COMO AUDIO Turntable(piano black) and I am very impressed by the build and sound. I was able to buy it new on Ebay for $199.99 with free shipping with a premounted Ortofon OM-10. So far it sounds wonderful and the price is so good for the starter system I am putting together...