Troubleshooting Table - Sharp TU-GA1U-S Service Manual

Is power cable properly connected to the main unit?
Is F701 normal?
Is F702 normal?
Is BU+5V line (pin (5) of P1701) normal?
Reconnect the wire harness, FFC, etc. in the set, and repeat
the check.
Are MDR (gray) and DVI (white) connectors of the system
cable properly connected to the Dispay and the AVC System?
YES
Is the power switch of the monitor ON?
YES
Is specified voltage available at S-Vcc+15V (pins (11) and
(12) of P1752), UR+10V (pin (5) of P1752) and CPU+10V
(pins (7) and (8) of P1781)?
YES
Is specified voltage available at D+1.8VCV (pins (3) and (4)
of P1703), D+3.3V (pins (9) and (12) of P1701) and D+5V
(pin (1) of P1703)?
YES
Is D_POW line normal? Are the pins
(46), (47) and (48) of IC1701 at "HI",
and the pin (5) of IC952 at "LOW"?
Check D_POW line.
Does OVP line voltage
fluctuate immediately after
the power is supplied?
NO
Reconnect the wire harness, FFC,
etc. in the set, and repeat the check.
TROUBLE SHOOTING TABLE
No power supply (Front LED is not ON)
NO
YES
NO
YES
NO
YES
NO
YES
No power-up (Front LED does not change from red to green)
NO
NO
NO
NO
YES
NO
Connect the power cable properly, and turn on the power.
Replace F701, and turn on the power. If the fuse is still
blown, replace VA701, D701, Q705 and Q706, and repeat
Replace F702, and turn on the power. If the fuse is still
blown, replace D701 and IC701, and repeat the check.
Is there any faulty part or short-circuit in BU+5V line?
YES
Remove the faulty part or short-circuit, and repeat the check.
Reconnect properly and turn on the power.
Set the power switch to ON, and turn on the power.
Are PS_ON (pin (6) of P1701) and EU_D_POWER (pin (2) of
P1702) at "HI" (3V or higher)?
YES
Is specified impedance available in S-Vcc+15V, UR+10V and
CPU+10V lines? (Measure the resistance between each +B
line and GND.)
YES
Are MOS-FET (Q1701, Q1702, Q1703, Q1704 and Q1705)
and IC952 normal?
YES
Replace IC1701.
25
TU-GA1U-S
TU-GAD
NO
Check IC902 and its peripheral
NO
Check PS_ON or EU_D_POWER
NO
Check the circuits in the faulty line.
NO
Replace faulty FET or IC.