The first thing to check is the CLKOUT signal. The CLKOUT signal will startup after the reset has finished. If the chip stops or suspends after the startup the CLKOUT signal will go away.(This signal can also be turned off by the firmware).
If you remove either the EEPROM or the contents of the EEPROM the chip should have a CLKOUT signal.If it does not the chip is not attempting a proper enumeration.