Oki Microline 520 - Page 257

Loopback Connector Configuration
1. Jumper the following pins together.
Pin 2 to Pin 3
Pin 4 to Pin 5
Pin 8 to Pin 11
Pin 6 to Pin 20
RS232-C Serial Loopback Test Connector
(DB25P Plug)
4-8-04.tif
Microline 520/521 Service Handbook 4 - 49 Failure Analysis
P/N 59257803