Nidek Medical CP-690, Service Manual

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4.7 The Chart Brightness is Uneven.
Does the unevenness show up in the
same area of the chart?
Y
Is the C lens ASSY dirty, burnt or
scratched?
Y
Adjust the position of the lamp (LED).
Is the chart brightness still uneven?
(See 6.3.)
Replace the screen.
Y
N
N
N
Clean the chart ASSY.
(See 5.13.1.)
Clean the C lens ASSY.
(See 5.13.2.)
If the dirt or burnt area can not be
cleaned, or the ASSY is scratched,
replace it. (See 5.10.)
Is the holder ASSY dirty, burnt or
scratched?
Y
Clean the holder ASSY.
(See 5.13.3.)
If the dirt or burnt area can not be
cleaned, or the ASSY is scratched,
replace it. (See 5.11.)
N
End