1969 Zenith 25ZT120 - AM Drop-Out, Sticking Power Button Issues

[videoroot]

I have a '69 solid-state Zenith 25ZT120 that's part of a console unit that I'm working on restoring. I've ran into a couple issues, and I'm hoping someone might be able to point me in the right direction, as I'm new-ish to vintage radios/electronics.

To start with the most simple issue: the power on button gets stuck in the "on" position. I believe this is called a "latching switch"--you push it to turn it on, and it stays pressed in, and then you press it again to turn it off. My unit has an issue turning off. I've tried cleaning it with electrical contact cleaner, but that doesn't seem to make a difference. If I pull the radio out, I can look at just the right angle to see it failing. There's this little 'V' that gets engaged via a lever when you press the switch on, and when you press it again, that lever is supposed to pull that 'V' back to the off position, but this doesn't always happen. I used to have better luck by removing the switch cover and pushing the rod underneath directly, but even that is giving me issues now.

I can't seem to find any info online about repairing this. It's very likely that my search terminology is wrong here, giving me bad results when googling. I would include pics, but I'm having issues getting a clear one with where it is on the unit. As an added bonus: It's possible that my switch is an aftermarket one, or at least someone messed with it in the past--it's covered in bunch of hot glue for whatever reason.

And while I'm here, might as well ask about another issue that I'm in the process of dealing with as well: I'm getting nothing, not even static, while tuned to AM channels 55 to 115. After 115, there's an audible pop noise, and then everything works as expected from there up.

I've already replaced all the electrolytic capacitors, and I'm in the process of slowly replacing the non-electrolytic molded-plastic/mylar capacitors that are throughout the unit. All the capacitors surrounding the AM IF, RF, Mixer, and OSC are of the disc variety though, so I don't currently have any replacements on hand. Any tips that would save me from simply brute-forcing a fix would be greatly appreciated!

Here you'll find a copy of the schematic. Apologies in advance for the quality; I plan to do a better, higher resolution scan in the future. Hopefully this'll suffice for the time being though.

Thanks in advance!