Thank you all for your helpful suggestions.
After several conversations with Rob Sherwood, who is a terrific gent, we've concluded that there is no easy way to repair this radio - there are fault LEDs turned on, on two boards - the IF-AF Amp board and the CPU board. The service manual unfortunately does not have any information to decode the LEDs and discern where they point to.
Rob echoed what DXACE1 mentioned below - JRC Equipment owners should keep their fingers crossed that nothing fails. Interestingly, Rob mentioned that even swapping out boards is not necessarily an option - he had a NRD-535 in for repair where he swapped a faulty board with a known good board but no luck - that board would not work in that particular radio, even though it worked in another 535.
@KlondikeMike - appreciate the pointer to your capacitor replacement kit. If you have one for a Yaesu FRG-7, you have a customer! :-)
Cheers & 73, raaj, Ki8JI