Hi @jm1000
Here's a link to the [https://archive.org/details/mega-cd-2-service-manual-1-of-2-a-4/Mega%20CD%202%20Additional%20Infromation%20A4/|schematics] that will help.
Scroll down to ''Download options'' and select ''PDF'' and then select which files you want to download.
The capacitor ID and values will be shown in the schematic so all you have to do is find the each capacitor ID in the schematic and match it to the capacitor ID on the board, to know its value.