Fon 460i All Lights Flashing

Randomly, my client comes into his office and finds that ALL LIGHTS are flashing on his Fon 460i (~0.5 sec, 50% duty cycle).  He removes the power from the phone and when he reapplies it, the phone boots normally. Coincidently, his PC is also in a random state as well.  It will not wake up.  It is set to NEVER sleep.  The power light is ON but the monitor is dark.  This is a Lenovo desktop.  He has to power the Lenovo down and then it comes up just fine.  

Does anyone know what might cause a Fon 460i phone to respond this way?

I rebooted the  FortiVoice FVC-70D switch today after 435 days of being online.