I upgraded the firmware on one of my One SPs without upgrading the post first and now when I power up the unit the power led flashes four times then goes off and I cannot connect through either port. Resetting the unit results in the usual 1-5-1 blink pattern but upon resealing the reset switch the power led flashes four times and then goes off. Does anyone have any suggestions for recovering this unit? I have tried the recovery method when the blink patter is 1-9-1 and I get no response.