  On July 30th, 2019 IceCube detected a high-energy astrophysical muon neutrino
candidate, IC-190730A, with a $67\%$ probability of astrophysical origin. The
flat spectrum radio quasar (FSRQ) PKS 1502+106 is in the error circle of the
neutrino. Motivated by this observation, we study PKS 1502+106 as a possible
source of IC-190730A. PKS 1502+106 was in a quiet state in terms of
UV/optical/X-ray/gamma-ray flux at the time of the neutrino alert, we therefore
model the expected neutrino emission from the source during its average
long-term state, and investigate whether the emission of IC-190730A as a result
of the quiet long-term emission of PKS 1502+106 is plausible. We analyse
UV/optical and X-ray data and collect additional observations from the
literature to construct the multi-wavelength spectral energy distribution of
PKS 1502+106. We perform leptohadronic modelling of the multi-wavelength
emission of the source and determine the most plausible emission scenarios and
the maximum expected accompanying neutrino flux. A model in which the
multi-wavelength emission of PKS 1502+106 originates beyond the broad-line
region and inside the dust torus is most consistent with the observations. In
this scenario, PKS 1502+106 can have produced up to of order one muon neutrino
with energy exceeding 100 TeV in the lifetime of IceCube. An appealing feature
of this model is that the required proton luminosity is consistent with the
average required proton luminosity if blazars power the observed
ultra-high-energy-cosmic-ray flux and well below the source's Eddington
luminosity. If such a model is ubiquitous among FSRQs, additional neutrinos can
be expected from other bright sources with energy $\gtrsim 10$ PeV.
