Dell 2135cn Service Manual page 697

Chapter 3 Removal and Replacement Procedures (RRPs)
3) Secure the HARN ASSY GFI GND with
the one screw (silver, 6m) to the DRIVE
ASSY SUB.
4) Engage the connecter (P/J221) of the
DRIVE ASSY SUB.
Go to the next replacement step:
Replacement 27 KIT DRIVE ASSY MAIN (PL7.1.98)
3 - 195
Version 
2008.02.01