Brother Facsimile Equipment MFC7420 - Manual (Page 250)

App. 1-2 Confidential
(2) Laser unit serial label
REGARDING X delay and Y delay
It indicates required delay amount for writing in each of main (X) and sub (Y) scanning direction
Location
LSU MODEL DISTINCTION
ERAME MANUFACTURER
AND MOLD DISTINCTION
T1 THE 1st. MOLD
Y3 THE 3rd. MOLD
POLYGON MOTOR DISTINCTION
INSPECTION MACHINE
SERIAL NUMBER
Y delay
X delay
Laser unit serial label