Sharp PN-K321, Service Manual

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PN-K321/K322B TROUBLESHOOTING 7 - 1
CHAPTER 7. TROUBLESHOOTING
No Description
1 THE POWER IS NOT SUPPLIED (THE LED DOES NOT LIGHT UP)
2
THE DISPLAY DOESN’T SHOW/ DISPLAY ABNORMALITY
3
THE BACKLIGHT DOES NOT LIGHT UP
4 SOUND IS NOT REPRODUCED/ REPRODUCED SOUND ABNORMALITY (PROBLEM
WITH MAIN UNIT)
5
CANNOT CONTROL RS-232C CONNECTION
6
THE RED LED BLINKS
7
THE LED LIGHTS UP IN ORDER OF RED -> GREEN -> RED -> GREEN
8
IMPLEMENTING COUNTERMEASURES TO DEFECTIVE PARTS
1. THE POWER IS NOT SUPPLIED (THE LED DOES NOT LIGHT UP)
:’13/Dec
No
Is the AC cord inserted to AC adaptor properly? Insert the AC cord to AC adaptor properly.
䚷
Yes
No
Is the DC jack properly inserted? Insert the AC cord or DC jack properly.
䚷
Yes
Is the power SW turned ON?
Is the power SW free from any abnormality? Abnormality found. Replace the abnormal part.
ẅ
No abnormality found.
Is the input voltage (approx. 19.5V) input to the input
connector CN1 on DC-DC PWB unit from the AC adaptor
properly? Abnormality found. Replace AC adaptor.
䚷
No abnormality found.
Are the powers BU5V (approx. 5V), MAIN12V (approx. 12V),
BKLTPOW19.5V (approx. 19.5V) and LCD12V (approx.
12V), output from the connector on DC-DC PWB unit? No Replace DC-DC PWB unit.
Yes
Check the Main I/F PWB and the related parts listed below
for any abnormality:
Abnormality found.
- Power cable Replace the abnormal part.
- Fuses F3200, F3201, F3202 (Are they blown out?) Replace the Main I/F PWB.
- RS232C communication (Is it capable of communicating
using RS232C?)
- Main I/F PWB
䚷
No abnormality found.
Check the Key PWB and the related parts listed below for
any abnormality
Abnormality found.
- Connection cable Replace the abnormal part.
- Key PWB Replace the Switch PWB.
[Caution]
If no signal is being input, the power-save function will
be activated that the output is blocked in a few
seconds.