Lenovo B50-45 Hardware Maintenance Manual - Lenovo B50-xx, B50-30 Touch Notebo - Page 25

Power system checkout, Checking the AC adapter, Checking operational charging

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Lenovo B50-30/B50-30 Touch/B50-45/B50-70 Power system checkout To verify a symptom, follow the steps below: 1. Turn off the computer. 2. Remove the battery pack. 3. Connect the AC adapter. 4. Make sure that power is supplied when you turn on the computer. 5. Turn off the computer. 6. Disconnect the AC adapter and install the charged battery pack. 7. Make sure that the battery pack supplies power when you turn on the computer. If you suspect a power problem, see the appropriate one of the following power supply checkouts: • "Checking the AC adapter" on page 21 • "Checking operational charging" on page 21 • "Checking the battery pack" on page 22 Checking the AC adapter You are here because the computer fails only when the AC adapter is used. • If the power‐on indicator does not turn on, check the power cord of the AC adapter for correct continuity and installation. • If the computer does not charge during operation, go to "Checking operational charging" on page 21. To check the AC adapter, follow the steps below: 1. Unplug the AC adapter cable from the computer. 2. Measure the output voltage at the plug of the AC adapter cable. See the following figure: Pin Voltage (V DC) 1 +20 2 0 2 1 Note: Output voltage for the AC adapter pin No. 2 may differ from the one you are servicing. 3. If the voltage is not correct, replace the AC adapter. 4. If the voltage is acceptable, do the following: • Replace the system board. • If the problem persists, go to "Lenovo B50‐30/B50‐30 Touch/B50‐45/B50‐70" on page 27. Note: Noise from the AC adapter does not always indicate a defect. Checking operational charging To check whether the battery charges properly during operation, use a discharged battery pack or a battery pack that has less than 50% of the total power remaining when installed in the computer. 21

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Lenovo B50-30/B50-30 Touch/B50-45/B50-70
21
To
 
verify
 
a
 
symptom,
 
follow
 
the
 
steps
 
below:
1.
Turn
 
off
 
the
 
computer.
2.
Remove
 
the
 
battery
 
pack.
3.
Connect
 
the
 
AC
 
adapter.
4.
Make
 
sure
 
that
 
power
 
is
 
supplied
 
when
 
you
 
turn
 
on
 
the
 
computer.
5.
Turn
 
off
 
the
 
computer.
6.
Disconnect
 
the
 
AC
 
adapter
 
and
 
install
 
the
 
charged
 
battery
 
pack.
7.
Make
 
sure
 
that
 
the
 
battery
 
pack
 
supplies
 
power
 
when
 
you
 
turn
 
on
 
the
 
computer.
If
 
you
 
suspect
 
a
 
power
 
problem,
 
see
 
the
 
appropriate
 
one
 
of
 
the
 
following
 
power
 
supply
 
checkouts:
•
“Checking
 
the
 
AC
 
adapter”
 
on
 
page
 
21
•
“Checking
 
operational
 
charging”
 
on
 
page
 
21
•
“Checking
 
the
 
battery
 
pack”
 
on
 
page
 
22
Checking the AC adapter
You
 
are
 
here
 
because
 
the
 
computer
 
fails
 
only
 
when
 
the
 
AC
 
adapter
 
is
 
used.
•
If
 
the
 
power
‐
on
 
indicator
 
does
 
not
 
turn
 
on,
 
check
 
the
 
power
 
cord
 
of
 
the
 
AC
 
adapter
 
for
 
correct
 
continuity
 
and
 
installation.
•
If
 
the
 
computer
 
does
 
not
 
charge
 
during
 
operation,
 
go
 
to
 
“Checking
 
operational
 
charging”
 
on
 
page
 
21.
To
 
check
 
the
 
AC
 
adapter,
 
follow
 
the
 
steps
 
below:
1.
Unplug
 
the
 
AC
 
adapter
 
cable
 
from
 
the
 
computer.
2.
Measure
 
the
 
output
 
voltage
 
at
 
the
 
plug
 
of
 
the
 
AC
 
adapter
 
cable.
 
See
 
the
 
following
 
figure:
Note:
 
Output
 
voltage
 
for
 
the
 
AC
 
adapter
 
pin
 
No.
 
2
 
may
 
differ
 
from
 
the
 
one
 
you
 
are
 
servicing.
3.
If
 
the
 
voltage
 
is
 
not
 
correct,
 
replace
 
the
 
AC
 
adapter.
4.
If
 
the
 
voltage
 
is
 
acceptable,
 
do
 
the
 
following:
•
Replace
 
the
 
system
 
board.
•
If
 
the
 
problem
 
persists,
 
go
 
to
 
“Lenovo
 
B50
‐
30/B50
‐
30
 
Touch/B50
‐
45/B50
‐
70”
 
on
 
page
 
27.
Note:
 
Noise
 
from
 
the
 
AC
 
adapter
 
does
 
not
 
always
 
indicate
 
a
 
defect.
Checking operational charging
To
 
check
 
whether
 
the
 
battery
 
charges
 
properly
 
during
 
operation,
 
use
 
a
 
discharged
 
battery
 
pack
 
or
 
a
 
battery
 
pack
 
that
 
has
 
less
 
than
 
50%
 
of
 
the
 
total
 
power
 
remaining
 
when
 
installed
 
in
 
the
 
computer.
Power system checkout
Voltage (V DC)
+20
0
Pin
1
2
2
1