Audio Amplifier
www.kitronik.co.uk
Is the speaker
making any kind
of sound?
Yes
No
Yes
Fault finding
flow chart
Start
Power up the board with it
connected to a music source
Stop
Is the speaker
playing the music
clearly?
No
Check
• IC1 is in the right way around
• For dry joints on the power /
speaker / input connectors
• The input connector is in the
right place
• IC1 for dry joints on one of the
following pins 3, 4, 5, 6, or 7
• IC1 for shorts between pins 3-
4, 5-6, or 7-8
• C1, C4, C5 & C6 for shorts
• C6 for dry joints
• C1 and C6 are in the correct
place
Is the volume
as expected?
Yes
Yes
Quiet
Check
• That resistor
R3 is in the
correct place
• R3 for dry
joints
• That C1 and
C3 are in the
correct place
• C2 for dry
joints
Check
IC1 for a short between pins
2-3
R1 & R2 are in the right
place.
• For a dry joint on C4, R2 or
IC1 pin 2.
• IC1 for a short between pins
1&2 or 6&7
Check
• The power clip &
batteries are
connected the right
way around
• C1 is in the correct
place
• The speaker &
power connections
are in the right
place
Does it “pop”
when the power
is connected?
No it’s
muffled or
unintelligible
noise
Is the speaker
making any kind
of sound?
Yes
No
Yes
Fault finding
flow chart
Start
Power up the board with it
connected to a music source
Stop
Is the speaker
playing the music
clearly?
No
Check
• IC1 is in the right way around
• For dry joints on the power /
speaker / input connectors
• The input connector is in the
right place
• IC1 for dry joints on one of the
following pins 3, 4, 5, 6, or 7
• IC1 for shorts between pins 3-
4, 5-6, or 7-8
• C1, C4, C5 & C6 for shorts
• C6 for dry joints
• C1 and C6 are in the correct
place
Is the volume
as expected?
Yes
Yes
Quiet
Check
• That resistor
R3 is in the
correct place
• R3 for dry
joints
• That C1 and
C3 are in the
correct place
• C2 for dry
joints
Check
IC1 for a short between pins
2-3
R1 & R2 are in the right
place.
• For a dry joint on C4, R2 or
IC1 pin 2.
• IC1 for a short between pins
1&2 or 6&7
Check
• The power clip &
batteries are
connected the right
way around
• C1 is in the correct
place
• The speaker &
power connections
are in the right
place
Does it “pop”
when the power
is connected?
No it’s
muffled or
unintelligible
noise
