Roland XP-50 not recognising JV-80 expansion cards

Hi I have a new to me Roland XP50. Seems to work well with audio and midi, and is in pretty good condition. The only thing is that expansion cards don’t seem to work. My understanding is that they should just appear as EXP A, EXP B etc… when selecting patches but they don’t. I can select User, Presets, and GM but not any EXP.

When I first opened the expansion area then I surprisingly found 2 boards inside Pop & Piano. The Pop one looked like the capacitor had leaked a little. I took both out and will have a go at the capacitor replacement on the pop one.
I also already had a 60s & 70s card, and another piano one which I think work, but they don’t seem to be recognised either in any slot or combination.

Its a good synth and was at a great price but the expansions would make it even better. Any ideas on a fix or maybe am I missing some obvious thing I should be doing to see the patches (couldn’t see anything in the manuals).

All any any help is much appreciated.

Clean the edge connections with some IPA. I believe there’s a known problem with the single capacitor on the expansion cards going bad with age. Try replacing that too.