1.
Power
off
the
computer,
and
unplug
the
ac
adapter
from
it.
2.
Turn
the
computer
upside
down.
3.
Remove
the
battery
pack
(see
“1010
Battery
pack”
on
page
77).
4.
Remove
the
backup
battery
(see
“Checking
the
battery
pack”
on
page
47).
5.
Measure
the
voltage
of
the
backup
battery.
See
the
following
figure.
Red (+)
Black (-)
Wire
Voltage
(V
dc)
Red
+2.5
to
+3.2
Black
Ground
v
If
the
voltage
is
correct,
replace
the
system
board.
v
If
the
voltage
is
not
correct,
replace
the
backup
battery.
v
If
the
backup
battery
discharges
quickly
after
replacement,
replace
the
system
board.
Checkout
guide
48
MT1864/1865/2525/2526/2527/2528