Geely Diagnosis Flow. Manual part — 73

289

No. 210 Poor timbre, low volume or noise jump when playing CD

Malfunction Cause

Solution

CD disk is too dirty or poor quality

①

Check CD disk surface, if it is too dirty or scuffed, then must be

①
replaced.

Check CD disk quality, if it is deformed or piratic, then must be

②
replaced.

Loudspeaker poor contact or

②
damaged

Check loudspeaker ext

③

erior, whether it is damaged, as well as

coil, whether it is burnt. Method: Measure the resistance by
multimeter, and the normal value shall be 4 Ohm. If the value
shows as infinite, then the loudspeaker was burnt and must be
replaced.

Volume controlli

③

ng knob damaged

Check CD player volume controlling knob, whether it is

④
damaged. As well as track controlling, whether it operates
correctly. And variable potentiometer of volume controller,
whether it is seriously worn, Replace CD-player assembly when
necessary.

Power supply unstable

④

Check voltage of CD

⑤

-player power supply, generally +B and

GND voltage shall between 10V and 14V. When ACC and GND
ignition switch locating at ACC or ON position, the value shall
between 10V and 14V.

Check CD

⑥

-player laser head serve motor driving voltage,

whether it is in normal range. Maintain it when necessary.

Laser head is too dirty or aging

⑤

After CD disk was inserted, inspect by infrared illuminator,

⑦
load motor action, when the disk positioned survey up/down
focus action of laser head, whether it radiates red/blue beam.
Check laser head component, clean laser head or replace
CD-player assembly when abnormal.

Poor timbre,

low volume or

noise jump

when playing

CD

CD

⑥

-player inner power amplifying

circuit malfunction

Power amplifier is a component of the vehicle son

⑧

ic equipmen

with most malfunction rate. It is mostly caused by integrated
package puncture.

Check power amplifier circuit supply voltage and load, as well

⑨
as the transient peak voltage generated by motor, whether they
are under normal value. Maintain and replace CD-player
assembly when necessary.

290

Check laser head, whether it is too

dirty or aging

Check volume adjusting

knob

Check loudspeaker, whether it is

poor conducted

Poor timbre, low volume or

noise jump when playing CD

Check CD disk, whether it is too

dirty

Check CD-player supply

voltage

Check the voltage between each pin of

power amplifier

Replace CD-player assembly

Inspect and maintain circuit or replace

CD-player assembly

Clean or replace CD-player

assembly

Maintain, modify

Replace CD-player assembly

Maintain, modify or replace

Replace CD disk

Normal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Normal

Normal

Normal

Normal

normal

291

No. 211 Low loudspeaker volume

Malfunction Cause

Solution

Loudspeaker poor performance

Loudspeaker poor performance, magnetic of alnico

①
reduced. The sensitivity of loudspeaker is mainly
determined by the magnetic of permanent magnet, the
quality of cone diaphragm and the level of assembly
process. Contact alnico with ferromagnetic and
estimate the magnetism, replace loudspeaker when
necessary.

Loudspeaker circuit poor contact or short circuit.

②

Check loudspeaker and CD-player external

connection, whether they are damaged. Measure with
multimeter, the resistance shall be 0 Ohm, disconnect
the connectors on both ends, and measure the
resistance between connection and body (earth lead),
of which value shall be infinite. If not, the circuit shall
be maintained or replaced.

Check loudspeaker exterior, whether it is damaged,

③
as well as coil, whether it is burnt. Measure the
resistance by multimeter, and the normal value shall
be 4 Ohm. If the value shows as infinite, then the
loudspeaker was burnt and must be replaced.

CD disk damaged

Check CD disk

④

quality, whether it is piratic. Replace to

genuine CD disk.

Check disk format or surface wearing level, and

⑤
replace timely when necessary.

Volume controlling potentiometer worn or
damaged

Measure the resistance between both ends of

⑥
volume controlling potentiometer. Connect multimeter
and rotate potentiometer slowly, meanwhile survey the
resistance variation, if there is no change or shows as
infinite, which indicates damage, then shall replace
CD-player

All or single

loudspeaker low

volume

CD -player inner power amplifier open or short
circuit

Check power amplifying circuit, measure the voltage

⑦
between each pin by multimeter. Check the signal from
front amplifying circuit. Mainly inspect the capacitance,
resistance of power amplifying circuit, as well as the
circuit and integrated package of circuit panel, whether
they are burnt. Replace CD-player when necessary.
power amplifying circuit, measure the voltage between
each pin by multimeter.

292

Volume controlling potentiometer damaged

Poor CD disk quatily

Loudspeaker poor performance

Loudspeaker low volume

Loudspeaker connecting wire poor

conducted or short circuit

CD-player assembly inner short circuit or open

circuit

Replace volume

potentiometer

Check and maintain

loudspeaker circuit

Replace CD disk

Replace loudspeaker

Replace CD player

Normal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Normal

Normal

Normal