MFJ-554 Classroom Code Practice Oscillator repair

There is a saying, "the journey is as important as the destination", and it applies when learning CW (Morse Code) - having an enjoyable and smooth tone to listen to is key (pun!) to a positive learning experience, while hacking away and trying to gain proficiency. My MFJ-554 yields a warm, pure sine wave tone, but stopped working correctly after what I surmise to be an electrostatic discharge (ESD) popped the input FET. In this video, I open up the MFJ-554, troubleshoot the issue and effect a repair. MFJ-554 user manual (no schematic is available): https://cdn.shopify.com/s/files/1/0289/7782/3843/files/MFJ-554.pdf?v=1586534075 73 de M0NJX (a.k.a. Queuerious Guy)