IBM 6151 Maintenance And Service Manual page 89

37x
512 KB Memory Expansion Option Module
Do not return to the Start of Call PIC, go to "Memory
Expansion Option PIC 2100" on page 3-2100-1.
38x
RT PC 5080 Peripheral Adapter
Additional Tests: Run the RT PC 5080 Peripheral Adapter
Checkout.
Removal Procedure: See Adapter Removal in Section 4.
Repair Checkout: Run the RT PC 5080 Peripheral Adapter
Checkout.
39x
4-Port Asynchronous RS-422A Adapter (Buffered)
Additional Tests: Run the RT PC 4-Port Asynchronous
RS-422A Adapter Checkout.
Removal Procedure: If the adapter is in the system unit, see
Adapter Removal in Section 4, otherwise
see the service information for the unit
where the adapter is installed.
Repair Checkout: Run the RT PC 4-Port Asynchronous
RS-422A Adapter Checkout.
(6/88) Problem Isolation Charts 3-0020-11