ATV 2 6.2.1 jailbreaked but black screen on TV now

Hi
I had to restore via iTune my ATV2 which was jailbreaked a year ago.
so i got a to 6.2.1

Today i wanted to jailbreak it again so i downloaded seas0npass Version 0.9.7 (865)
I have a Mac EI Capitan 10.11.2
iTune 12.3.2.35

I had several errors during the jailbreak essentially at DFU step with message like “failed to reste USB”

i had to start several time and finally the jailbreak seemed to work as i got a message " firmware restore successful"
in fact from seas0npass log file i can see :

2015-12-23 07:35:41.983 Seas0nPass[10131:2815076] finished with status: Successful
2015-12-23 07:35:41.983 Seas0nPass[10131:2815076] Firmware restore successful!
2015-12-23 07:35:41.000 Seas0nPass[10131:160b]: Unregistering client ID 1
2015-12-23 07:35:42.000 Seas0nPass[10131:be6f]: Looking up device with muxID:10
2015-12-23 07:35:42.000 Seas0nPass[10131:be6f]: Muxed device disconnected
2015-12-23 07:35:42.000 Seas0nPass[10131:be6f]: RestoreOS mode device disconnected
2015-12-23 07:45:41.365 Seas0nPass[10131:2815076] last used bundle: AppleTV2,1_5.3_10B809
2015-12-23 07:46:28.728 Seas0nPass[10131:2815076] last used bundle: AppleTV2,1_5.3_10B809

so i disconnected ATV from my Mac and connected to my TV via HDMI.
when connected the power cable the Apple logo appeared on the TV screen for few seconds and then dissappeared
now since 45 minutes there is black screen on TV and the light on ATV is blinking.

can anyone please help ?

thanks

I haven’t tried Seas0nPass 0.9.7 on 5.3 or El Capitan. I have had success using Seas0nPass 0.9.6 and 5.3 using Yosemite 10.10.5 for an unteathered JB. Also have had success with Seas0nPass 0.9.7 and 6.2.1 using Mavericks 10.9.5 for a teathered JB. I setup partitions on my MacBook each with different versions of OSX ever since Seas0nPass issues with Lion which were never fixed.