Lenovo ThinkPad T500 Hardware Maintenance Manual - Page 39

Checking, backup, battery

Page 39 highlights

Checking the backup battery Do the following: 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 63). 4. Remove the backup battery (see "1100 Backup battery" on page 79). 5. Measure the voltage of the backup battery. See the following figure. Red (+) Black (-) Wire Red Black Voltage (V dc) +2.5 to +3.2 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. General checkout 31

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174
  • 175
  • 176
  • 177
  • 178
  • 179
  • 180
  • 181
  • 182
  • 183
  • 184
  • 185
  • 186
  • 187
  • 188

Checking
the
backup
battery
Do
the
following:
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
63).
4.
Remove
the
backup
battery
(see
“1100
Backup
battery”
on
page
79).
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.
General
checkout
31