Brother HL-2600CN Service Manual page 224

4.1.6 IOD1 PWB 2
1) Remove the set screws ST3X6 (4 pcs.) to remove the shield upper from the printer.
2) Disconnect all the harness connectors (15 pcs.) connected to the IOD1 PWB 2.
3) Remove the set screws ST3X6 (6 pcs.) to remove the IOD1 PWB 2 from the printer.
Shield upper
IOD1 PWB 2
Fig.7-16
PRECAUTION 
When handling the IOD1 PWB 2, take care that no damage is caused due to electrostatic
charges.
VII-12