Improving Roland R-8 pad sensitivity

[ʝɵʝɵ]

I got a Roland R-8 for very cheap as it was assumed to be partially broken, as some pads were acting strangely (no sound at all or hard-panned sound, as if one audio channel was dead). Turns out that they were just configured weirdly, and a factory reset made them behave normal again. Yay!
However, even after that the pads do feel a bit uneven when tapping them lightly, and running the R-8 in test mode confirms that some pads don't react to very light touch at all while others do recognize being pressed. I couldn't find any information on whether this can be improved without completely swapping out the pad contacts. Has anyone managed to improve pad responsiveness on an R-8 (or R-5) before? The pad contacts appear to consist of two silicone-like mats with contacts printed on them. The mats stick together nicely as if they are glued together, so without knowing what I'm doing I'd rather not take them apart. But maybe someone here has done that before and can confirm if cleaning the contacts between those two mats helps at all with my problem?