The tray mechanism is broken. You probably have it not closing completely and thus not hitting on the 2 position switch. For one side it means "closed" for the other "open". The middle means the door is half open.
The DVD drive CPU is programmed to aways attempt to close the door if it's not closed upon power up, even if the main CPU does not start up...
SCPH-10000_GH-001 SCPH-15000_GH-003 SCPH-18000_GH-008 SCPH-30001_GH-005 SCPH-30000_GH-016(V4) SCPH-30001_GH-010(V4)
2xSCPH-10190, 2xSCPH-10350, 2xSCPH-10280
"**** j0 hackers!"
-Sjeep (As seen on TOXIC OS ELF...)