C1765nfw error code 019-402

Good morning,

My customer's Dell C1765nfw MFP displays error code 019-402. According to what I could fine on the other boards, pertains to a drum needing to be replaced. However, I cannot find a service manual for this unit. So my question are as follows;

1.  is this a unit manufactured by you (Dell) or another manufacture (i.e. Lexmark or Xerox)?

2. If the later, I need the manufacturer and model number.

3. If not, how do I replace the drum unit?

Thank you.

Rudy