Samsung YP-Q1 Service Manual page 18

4-1-2 No Sound
Symptom No output at earphones
Check if the earphones are normal. / Check the cold solder on the earphones jack.
Major Checklist
1 Check if the DCVDD POWER input to the CODEC is proper. (Check for 1.8V)
2 Check if the AVDD1, AVDD2 power input to the CODEC is proper. (Check for 3.0V)
No Sound
Are the earphones
normal?
Yes
1
Is audio codec
voltage a normally?
DCVDD: 1.8V Check
Yes
Does the YEPP
Logo Song play?
Yes
Do R/L-CHs output
normally?
Yes
Are there skips and
noises?
Yes
Are the skips and
noises even when playing
another file?
Yes
Does the
same symptom persist
even after upgrading the
firmware to the latest
version?
Yes
Replace the BOARD
(needs thorough examination).
Samsung Electronics
No
symptom persist even
after replacing the
No
voltage a normally?
AVDD1, AVDD2: 3.0V
 Refer to wave pattern
image of Fig. 4-2.
No
supplementing the solder
No
Does the same
earphones?
2
Is audio codec
Check
Does it play after
on the jack?
Yes
Troubleshooting
No
Replace the earphones
No
Power Defective
No
Check if FET700 is shorted.
Yes
Check if IC701 is shorted.
Yes
No
No
4-5