FT-5100 SubBand off frequency???

My Yaesu FT-5100 subband frequency is off by about 5KHz.
The reference frequency and second mixer frequencies
seem to be right on. That leaves the two ceramic filters
in the subband detector, the IF filter and the demodulator.
I'll have to set up a sweeper to figger out which one.

There doesn't seem to be anything tweakable except the
main ref frequency. Seems like they'd need really tight
control of the ceramic resonator frequencies to make this work.
I'm guessing that substitution of parts is out for this reason.

Resetting the radio didn't help.

Is this a typical ceramic resonator failure mode?
Other ideas?

Or am I missing something?
I don't have the service manual, so if there is a calibration
constant that can be set, I'd appreciate hearing about it.
A PDF of the service manual would also be appreciated.

This is a recent used acquisition, so I don't know the history.

Thanks, mike
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