Series involving bessel functions

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I'm dealing with the following type of series:

$$S = \sum_{m = 1}^{\infty} a_{m} \frac{J_{\nu+\lambda}(m \pi)}{m^{\lambda}},$$

where $\sum_{m = 1}^{\infty} a_{m} < \infty.$ There is anyway to know the sign of $S$?

Thanks in advanced