  In an extended effective operator framework of isospin violating interactions
with light mediators, we investigate the compatibility of the candidate signal
of the CDMS-II-Si with the latest constraints from DarkSide-50 and XENON-1T,
etc. We show that the constraints from DarkSide-50 which utilizes Argon as the
target is complementary to that from XENON-1T which utilizes Xenon. Combining
the results of the two experiments, we find that for isospin violating
interaction with light mediator there is no parameter space which can be
compatible with the positive signals from CDMS-II-Si. As a concrete example of
this framework, we investigate the dark photon model in detail. We obtain the
combined limits on the dark matter mass $m_{\chi}$, the dark photon mass
$m_{A'}$, and the kinetic mixing parameter $\varepsilon$ in the dark photon
model. The DarkSide-50 gives more stringent upper limits in the region of
mediator mass from 0.001 to 1 GeV, for $m_{\chi} \lesssim 6$ GeV in the
($m_{A'}$,$\varepsilon$) plane, and more stringent constraints for
$m_{\chi}\lesssim 8$ GeV and $\varepsilon \thicksim 10^{-8}$ in the
($m_{\chi}$,$m_{A'}$) plane.
