I recently bought an S2000 cheap just for the cover. Seller said the tuner was not powering on. But it is working! In shipment, the 6X4 tube came loose and broke. I got another in there. FM sounds fine and so does AM. However, on AM at certain segments of the band, I hear a "motor boating" kind of distortion. The 6X4 glows inordinately brightly. So I'm wondering if I should change the capacitors and those 470 ohm 10 watt resistors. Haven't yet checked voltages on that tube. I should mention, I'm a mere novice at this.