[Eric Adams]

Hello everyone,
 After our move to Florida, I'm finally getting back to my radios and of course I've run into a problem.
Its A Zenith G725 AM/FM. I did a recap, checked all resistors and replaced any out of specs, tested the tubes and replaced 2. I did an alignment also. Everything was fine for about 2 days. While the FM works fine, as I was listening to the local AM station it just stopped receiving. I am now able to pick up only one AM station and it's not the closest to me. BTW, I re-tested all the tubes and they are OK.
Does anyone have any ideas as to what happened? 
Here is the schematic:  Zenith Radio Corp.: G725 (nostalgiaair.org)

It's good to be back,

[MrFixr55]

Hi Eric,

The one station that can be received, is it toward the upper end of the AM Band? When the set was working correctly, were you able to receive stations at a higher frequency than the one station that you can receive now? Does the FM still work normally?

If FM works correctly and there are no receivable stations above the one that you can receive when the radio was working correctly, the issue may be shorts between the rotor and stator of the AM section of the tuning cap. Aluminum can oxidize and short out between the plates. If this is not the case, check the band switch. I can't see a defect in the 12AT7 convertor tube that would allow FM reception but not AM reception. Neutralization may be an issue, but I may be stretching it here.