I recently purchased 2 Sony SPORTS WM-F73 FM/AM Radio Cassette players that had bad belts. After replacing the belts and testing, I found that the radio played good on both units, but the cassette volume on both units was extremely low. (Barely audible) I did try numerous tapes (in case you're wondering). I bought another one on eBay, with the same results. What should I look for?