Sharp VN-EZ1U Service Manual page 17

9. TROUBLESHOOTHING
POWER CIRCUIT TROUBLESHOOTHING
The power cannot be turned on.
Check SW901.
I
Is
voltage output between the pins (2), No
(3) (6) and (7) of Q921 and TL1922?
l
Check battery and AC adaptor.
Check battery terminal.
Yes
Check F901 and F902.
Is OV applied to the pin (13) of IC901
No B Check periphery of Q924. Check SW291 1.
when power is turned on?
Is PCNTl at Hi level?
Yes
Check microcomputer circuit.
Is triangular wave of approx. 700 mVp-p
No
l
Check C906, R902 and R905.
output at the pin (17) of IC901?
Check C903 and R910.
Yes
Is voltage supplied to the emitter of
'No
Check F903, F904 and F905.
Q930, Q906 and Q907?
l
Check L904 and D906.
1
Yes
Is 3.3V output to TL943?
No
Shorted load of 3.3V line.
Yes
l
Check Q906, D905, L905 and pins (8)
and (9) of IC901.
v
Is 2.5V output to TL944?
No
Shorted load of 2.5V line.
a
Yes
l
Check Q928 and IC903.
L
l
Is 5.OV output to TL919 and TL989?
Yes
Shorted load of 5V (CCD) and 5V (TFT) line.
Check IC904, Q930, Q911, IC906, Q908, D906,
L911, L904 and pins (11) and (12) of IC901.
Shorted load of 3.3V (MEDIA) line.
Is 15V applied to TL923 and TL983?
Is 7.5V applied to TL981?
Is -9V applied to TL927?
Is -15V applied to TL977?
No
l
Shorted load of 15V (CCD), -9V (CCD), lSV(TFT),
7.5V (TFT) and 15V (TFT) line
.
Check Q907, T901, 0907,0908, L907, L908, L909,
L910 and pins (15) and (16) of IC901.
Is back light lit?
Does T903 oscillate?
I Yes
No
1
+ Check Q922, Q923, Q925,
Q929, L913 and C946.
IC205 TROUBLESHOOTHING
Is the terminal (21), (28), (32) (33) (47) No -,
Check power circuit.
(48) (50) (82)s GND, (9), (29) (34) (35)
Check L208.
(40) (49) (77) or (79) of microcomputer
power [3.3V] is normal.
RSTX(75)"H" Check IC204 and D201.
Is clock (approx. 4 MHz) supplied to pin No
b Check IC201 oscillation.
(80)?
(24.5454MHz)
I Yes
l
&eoi;ration keys (36) (37) and (38) No b Check relevant key.
Check R2901 -R2908 and R291 O-R291 2.
Check connection lines of IC205 and lC206.
I Yes
*
Is IC2901 communication normal?
No
Check connection lines of lC205 and lC2901.
l
Check IC2901 for oscillation (32 kHz).
I
I
Yes
I I -
.
r
I
l
Is IC201 communication normal?
I Yes
No
b Check pins (l), (2), (99) (loo), (83)-(90)
and periphery of IC201.
No
+ Check pins (91)-(98), (83)-(90) and
periphery of IC203.
Defective IC205. Short circuit of each pin.
1 IC205 normal.
Yes
CCD TROUBLESHOOTHING
1 Turn mode SW to MOVIE.
No
1 Is power voltage no-1 d Refer to the troubleshooting of the
I .
I Yes
+
I
1 power supply. I
Is clock signal supplied to TL15, TL16 No
l
Check IC35 and periphery of IC201.
and TL17?
Check
CCDFPC.
I
Yes
Is pulse signal supplied to TLG-TLlO? No
b Check IC31 and its periphery.
Check CCDFPC.
Yes
Is signal supplied to (l)-(4) and (12)-
Check ICl peripheral circuit.
I
(141 of Cl?
b48 or LCD unit is defective.
1
ICl is defective.
Check Ql.
CCD unit is normal.