Cisco uBR10000 - rf-status DOWN

Hello!
Cisco uBR10000 Version 12.2(33)SCJ2a
card 7/0 ubr10k-clc-mc2020v license 20X20
card 7/1 ubr10k-clc-mc2020v license 20X20
card 8/0 ubr10k-clc-mc2020v license 20X20
card 8/1 ubr10k-clc-mc2020v license 20X20
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cable load-balance docsis-group 800
downstream Integrated-Cable 8/0/0 rf-channel 0-3
downstream Integrated-Cable 8/0/1 rf-channel 0-3
upstream Cable8/0/0 0-3
method utilization
threshold load 85
threshold stability 85
init-tech-list 3
interval 80
!
cable load-balance docsis-group 801
downstream Integrated-Cable 8/0/2 rf-channel 0-3
downstream Integrated-Cable 8/0/3 rf-channel 0-3
upstream Cable8/0/1 0-3
method utilization
threshold load 85
threshold stability 85
init-tech-list 3
interval 80
_______
controller Integrated-Cable 8/0/0
rf-channel 0 cable downstream channel-id 1
rf-channel 0 frequency 378000000 annex A modulation 256qam interleave 12
rf-channel 0 rf-power 50.0
no rf-channel 0 rf-shutdown
rf-channel 1 cable downstream channel-id 2
rf-channel 1 frequency 386000000 annex A modulation 256qam interleave 12
rf-channel 1 rf-power 50.0
no rf-channel 1 rf-shutdown
rf-channel 2 cable downstream channel-id 3
rf-channel 2 frequency 394000000 annex A modulation 256qam interleave 12
rf-channel 2 rf-power 50.0
no rf-channel 2 rf-shutdown
rf-channel 3 cable downstream channel-id 4
rf-channel 3 frequency 402000000 annex A modulation 256qam interleave 12
rf-channel 3 rf-power 50.0
no rf-channel 3 rf-shutdown
!
controller Integrated-Cable 8/0/1
rf-channel 0 cable downstream channel-id 5
rf-channel 0 frequency 410000000 annex A modulation 256qam interleave 12
rf-channel 0 rf-power 50.0
no rf-channel 0 rf-shutdown
rf-channel 1 cable downstream channel-id 6
rf-channel 1 frequency 418000000 annex A modulation 256qam interleave 12
rf-channel 1 rf-power 50.0
no rf-channel 1 rf-shutdown
rf-channel 2 cable downstream channel-id 7
rf-channel 2 frequency 426000000 annex A modulation 256qam interleave 12
rf-channel 2 rf-power 50.0
no rf-channel 2 rf-shutdown
rf-channel 3 cable downstream channel-id 8
rf-channel 3 frequency 434000000 annex A modulation 256qam interleave 12
rf-channel 3 rf-power 50.0
no rf-channel 3 rf-shutdown

execute the command:sh cable rf-status

8/0/0 0 UP N/A 0 0
1 UP N/A 0 0
2 UP N/A 0 0
3 DOWN Yes 0 1 Jan 21 18:17:52
8/0/1 0 DOWN Yes 0 1 Jan 21 18:17:47
1 DOWN Yes 0 1 Jan 21 18:17:47
2 DOWN Yes 0 1 Jan 21 18:17:47
3 DOWN Yes 0 1 Jan 21 18:17:47

turned on and off rf-channel, after 2 minutes again DOWN.

You can tell what could be the problem.