Samsung RS21 Service Manual page 57

Diagnostics
3) Without sound of buzzer operation
Refer the description of
Test function in the manual
for the Forced operation.
Start
Does it sound
'Ding-Dong'if you press a button
on front panel?
NO
Does i t make a sound of ' d oor-open' al a rm
when you are openi n g the door of freezer or fri d ge
more than 2 mi n ?
NO
Is the bent or go-out of the buzzer
in the main PCB?
NO
Are signals coming
out of MICOM No. 21 in a 1-sec cycle
after the Forced operation?
YES
Is signal of Q801
Base ouputted with 1 sec. intervals
in the condition above?
YES
Did lead of a
component fall on the vibration plate
of buzzer?
NO
The main PCB and buzzer are normal
57
YES
Main PCB is normal; buzzer normal.
YES
Check the panel PCB with the
reference of 'how to check panel
display'.
YES
Buzzer is broken – replace it.
NO
Replace the main PCB.
(failure of MICOM)
NO
Check the state of pattern connection
between MICOM No.21 and Q801.
(Check Open/Short)
YES
Poor buzzer is broken down or
replace the buzzer.