Update:
The cabinet has been updated to 4.98. We removed all cards we are not using and put another 16DLI2 in cabinet 1. We also replaced the cables between the cabinets with shorter high speed cables.

Most, but not all, extensions in cabinet 2 (S2 and S3) have no lights on the phone. The top indicator light doesn't come on when you pick up the handset. The call lights don't turn green when you pick up a line. Even the speaker phone light doesn't come on when you hit the button.

A ticket has been opened with Samsung and a copy of the DB sent in. The technician thinks the EPLD version may have something to do with it. Samsung is asking him to call in to distributor support.

Here's our current cabinet setup:
OS7400 (v4.98) as Cab1.
LP Version: '14.04.01 V2.04
Option Board 1: CRM
Option Board 2: CID2
Option Board 3: MISC
Board EPLD Version: V01
Board PCB Version: V01
Card EPLD Version: V09
Card PCB Version: V01

S1: TEPRI2 ['11.05.03 V4.29]
S2: TEPRI2 ['11.05.03 V4.29]
S3: MP40 ['16.08.01 V4.98]
S4: SVMi20E ['09.04.22 V5.03]
S5: 16DLI2
S6: 16CLI2
S7: 16DLI2
S8: 16DLI2
S9: 16DLI2
S10: 16DLI2
S11: 16DLI2

OS7200 as Cab2
LP Version '14.04.01 V4.33
Option Board 1:
Option Board 2:
Option Board 3:
Board EPLD Version: V00
Board PCB Version:
Card EPLD Version: V01
Card PCB Version: V01

S1: NO CARD
S2: 16DLI2
S3: 16DLI2
S4: NO CARD
S5: NO CARD

"Try not to become a man of success, but rather try to become a man of value" ~ Albert Einstein