It could be a failure of the flat cable that connects the small board to the main board.
Originally Posted by belek666
The small board has the following parts of the system:
System controller - controls the power on of the system
EEPROM - Contains Serial number of the PS2 unit(what people call DNAS), laser unit/DVD drive settings, DVD player settings and user settings
Battery and clock chip.
More than half of the power supply regulator circuits (reduce 12V from main power supply to the voltages the chips need)
So if the flatcable fails you get all sort of weird effects such red or blue blinking lights, DVD not ejecting, Model number being detected as "Unknown" DVD drawer being kicked out in the speed of the light if one press eject ... etc ...
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...)