RICOH MP C3500 Black Developer changing

[@OnePlus-wg6ti]

Hello sir.
The video was superb.
Please add more such videos.
Thanks

[@jimmyl1344]

Thank you for sharing. Would you show me where to buy developer for MPC4503 ?

[@hwang9877]

Great instruction. When do we need replace developer?

[@ricohservice6653]

Hi! When the copier makes dirty gray pages