Lcd; Panel Lamp Replacement - Yaesu FT-2500M Technical Supplement

Case
Disassembly and PCB
Access
LCD
€s
Control Unit
Access
3
To
access
the Control Unit and Display
Unit
first
remove the VOL, SQL and
dial
knobs
by
gently pulling them outward.
Next remove two
screws
from
each side of
the
top cover and
one
from
the rear.
Tilt
the rear
of
the cover upward, then slide
it
out from
the
chassis.
Note that the single rear screw is
dif-
ferent from the other four, be sure to
reinstall
it
in the correct location.
Be
careful not to lose the
plastic plug covering the cable entrance
cutout
in the
chassis.
Remove the
two hex bolts
from
the
front panel
using
a 3.5
mm hexagonal driver, then gently
loosen the
front
panel.
Remove the
two flat ribbon
cables
by using
a
small screwdriver
or fingemail
to
slide the
release clamps
forward on both sides
of
the
cable connector.
After
releasing
both
cables,
gently separate the
front panel from the main
chassis and place
it
on
a
soft surface to
prevent
the clear display from marring.
a
Lithium
Backup
Battery
Replacement
The
lithiumbackup battery
should not require
servicing
for
a
period of
several years, howeveq,
to replace the cell, order
Yaesu
P/N
Q9000552.
O First note the location and tab polarity
of
8T2001,
mounted over the CNTL Unit
micro-
processor. To
remove the
old
cell, carefully
unsolder
each
terminal from the CNTL Unit
PCB
and
lift it
free.
Dispose
of
lithium
batteries
according
to
regula-
tions in your
area,
and ensure small children can-
not
play with
or
accidentally ingest thebattery.
O Mount
the replacement cell similarly, observ-
ing proper polarity when installing it.
Next,
place the plastic
insulating seal (P/N
R8118690)
on top of the
cellbypeelingbackthe
cover
to
expose
the adhesive backing, then
pressing
it in
place.
Panel Lamp Replacement
The LCD and controls are
illuminatedby four
10-V incandescent
miniature lamps.
If
these re-
quire replacement, they canbe ordered
fromyour
Yaesu
dealer
(P/N
Q1000083).
fl
First remove the front panel
as
previously de-
scribed. Note the location of the four lamps,
as
indicated below.
f:
W/Spacer
i:
W/O
Spacer
fl
To remove a
failed lamp,
use a
low
wattage
soldering
iron and
forceps
to
unsolder
and
free
each
lead, then gently
lift
the
bulb out of
the hole.
o
tr
FT-2500M
Technical
Supplement
2-1