Hi I have a Marantz AV9000 DD preamp and whenever the power is
removed, all settings are lost and back to factory defaults. I have
the service manual and there is no battery backup. However, there is
a 1F 15v capacitor which seems to be involved in the backup function.
My question is would such a capacitor fail after about 4 years? And
does anyone know where I could find one?

Thanks