I stumbled across this item on the Japanese Roland site as translated by Google Translate:

To Expansion Board SR-JV80 Series Customers (Published January 27, 2017)

Thank you very much for your patronage of our products on a daily basis.

The Expansion Board SR-JV80 series has been in production for more than 20 years since the initial production, electrolyte in use may rarely leak due to aged deterioration of the electrolytic capacitor used.

If electrolyte leaks out, in the worst case there is a risk of smoking.
Customers who are currently using the SR-JV80 series with sound module or synthesizer should stop using them immediately.

If you continue to use this SR-JV80 series in the future, please consult the Roland customer consultation center.

Roland Customer Consultation Center 050-3101-2555
* Follow the voice guidance, please press the repair reception desk “1 #”.

Reception hours: Monday to Friday 10: 00 ~ 17: 00 (excluding holidays and our defined holidays)

We deeply apologize for any inconvenience to our customers who love their products. From now on, we will strive to further improve the quality. Thank you for your consideration.

Electrolytic capacitors do not age well. By now, we have all been bitten by low quality capacitors which have failed after a few years of operation. I’m sorting through old computer equipment and I’m amazed that much of it is still operational nearly 30 years later. Not much of a guarantee, however.

I couldn’t help but chuckle at the chief concern in Roland’s warning message: Don’t smoke around our old JV80 gear with expansion boards. Clearly, this was written by (very polite) lawyers! If I did smoke, I would sooner give up the cancer sticks than give up my XP-60.