[j-nsp] Strange PIC Problem with 1xG/E, 1000 BASE-SX

[Zvezdelin Vladov]

Dear List,

I have very odd problem with one  1000 BASE-SX PIC with an old m7i.
Here is the Hardware inventory:
Item             Version  Part number  Serial number     Description
Chassis                                36390             M7i
Midplane         REV 04   710-008761   XXXX            M7i Midplane
Power Supply 0   Rev 05   740-008537   XXXX          AC Power Supply
Routing Engine   REV 11   740-009459   XXXX        RE-5.0
CFEB             REV 04   750-010463   XXXX          Internet Processor II
FPC 0                                                    E-FPC
  PIC 0          REV 10   750-003163   XXXX            1x G/E, 1000 BASE-SX
  PIC 2          REV 10   750-003163   XXXX            1x G/E, 1000 BASE-SX
  PIC 3          REV 06   750-007641   XXXX            1x G/E IQ, 1000 BASE
    Xcvr 0                NON-JNPR     XXXXXXXXXX      SFP-LX
FPC 1                                                    E-FPC
  PIC 2                   BUILTIN      BUILTIN                    1x Tunnel
  PIC 3          REV 07   750-009099   XXXXX           1x G/E, 1000 BASE
    Xcvr 0       REV 01   740-013111   XXXXX         SFP-T
Fan Tray                                                 Rear Fan Tray

2) If in the above configuration, instead of PIC 3, FPC0, I put this PIC:
PIC 3          REV 01   750-005091   XXXXX            1x G/E, 1000 BASE-SX

I'm starting to experience very strange PIC problems, manifesting in:
2.1) Input Errors
2.2) Carrier Transitions (happening quickly)
2.3) Reduced performance in terms of bandwidth (500mbps total via the PIC,
 but the Number of Packets/s almost inline with the normal packet load)

If I put back the above IQ PIC back, everything goes back to normal.

3) The Same Faulty PIC 3  REV 01   750-005091   XXXXX            1x
G/E, 1000 BASE-SX, if
moved around the slots, of the same above chassis, doesn't make a change - i.e.
again the same problems.

4) The Same Faulty PIC 3  REV 01   750-005091   XXXXX            1x
G/E, 1000 BASE-SX, if
put in another m7i chassis, but left alone on the FPC - works like a
charm, no errors, no carrier drops,
no problems.

Any ideas, what could be the problem?

Thank you,
Zvezdelin Vladov