C
HAPTER
3. M
AINTENANCE
P
ROCEDURES
3-37
02.9631.0010
CONFIDENTIAL
15 Jan 98
3.2.2.6
Intensity Iris Not Working Properly
Step 1.
Open electronics chassis to gain access to motherboard.
Step 2.
At motherboard, ensure good yoke cable connection.
Step 3.
Remove head assembly covers to gain access to YTB.
Step 4.
At YTB, ensure good yoke cable and iris motor wire
connections.
Step 5.
At electronics chassis, replace CIB with known good board.
a. If replacement solves problem, then problem is with
removed control interface board.
b. If replacement does not solve problem, re-install removed
control interface board and continue with next step.
Step 6.
At iris assembly, inspect iris belt. Replace belt as necessary.
Refer to Brightness/Focus Bulkhead Belt Removal and
Replacement paragraph.
Step 7.
At sensor bracket, inspect whether bracket is rubbing on iris
surface. Bend bracket back or replace as necessary.
Step 8.
Rotate iris by hand. If iris does not move or is rough, replace
iris assembly. Refer to Brightness/Focus Bulkhead Brightness
Iris Removal and Replacement paragraph.
Step 9.
If symptom persists, replace Yoke cable. Refer to Yoke Cable
Assembly Removal and Replacement paragraph.
