Sorry, I meant the PCB modules the capacitors are physically mounted to. These mini-modules are made of a ceramic type material. The surface-mount electrolytic capacitors themselves are the silver can-type, mounted directly onto the modules.
As you can see in the attached example, the four in the middle of the photo have leaked. I'm not sure if your machine has this exact same module, or ones like it, but definitely something to look out for.
[Picture pulled from
this post]