If you turn your Oki C5300 printer on and get the following error message on the control panel display:
SERVICE CALL
020:FATAL ERROR
The firmware DIMM is faulty. This is quite a common fault with this printer and is easy to repair.
This is a common fault with the HP LaserJet P3005. When you turn the printer on, it will hang either at the memory count or with the HP logo on the control panel display. It might also have a blank display or show a DIMM error.