tried that and also other commands: no errdisable detect cause gbic-invalid
no luck - still both ports down
Juniper uses http://www.juniper.net/documentation/en_US/release-independent/junos/topics/reference/general/cable-ex-series-sfp-plus-direct-attach.html these cables and two of them are plugged to 4900 to these modules:
https://www.amazon.com/Cisco-CVR-X2-SFP10G-SFP-ADAPTOR-MODULE/dp/B0030VM08Q
So theoretically they should both work.