IBM 6151 Maintenance And Service Manual page 122

Blx
IBM Token-Ring Network RT PC Adapter Cable
Additional Tests: None
Removal Procedure: See Adapter Removal in Section 4.
Repair Checkout: Run the Token-Ring Network RT PC
Adapter Checkout
B2x
IBM PC Parallel Printer Cable
Additional Tests: None
Removal Procedure: See Adapter Removal in Section 4.
Repair Checkout: Run a customer print job.
B3x
RT PC Serial Printer Cable (9 Pin)
Additional Tests: None
Removal Procedure: See Adapter Removal in Section 4.
Repair Checkout: Run a customer print job.
3-0020-44 Service Manual