HP 3325A Frequency Synthesizer Repair: keys, caps and PLL trouble

The oldie (1979) but goodie HP 3325A is a Fractional-N frequency synthesizer with 9 digits of frequency resolution to play with. But my auction-salvaged model predictably does not work. Let's make it chooch again! The bonus Fractional-N video explains the genius principle of how the synthesis works:    • HP 3325A Bonus Material: Fractional-N Freq...   Our sponsor for PCBs: https://www.pcbway.com Support the team on Patreon:   / curiousmarc   Buy shirts on Teespring: https://teespring.com/stores/curiousm... Learn more on companion site: https://www.curiousmarc.com Contact info: https://www.youtube.com/curiousmarc/a...