Sharp Aquous 4T-B70CJ1U, Service Manual, Page: 29 / 63

4T-B70CJ1 TROUBLE SHOOTING 4 - 27
2. HOW TO RESPOND BY TROUBLE SYMPTOM (IN CASE OF DEFECTIVEMODE)
No Description
1 No Power (front LED failure to light up) or no startup (front LED failure to turn red to green)
2 With [RF]signalinput No video onscreen(1)
3 With <Video>signalinput No video onscreen(2)
4 With <HDMI1/HDMI2>signalinput No video onscreen(3)
5 No audio heard (1)
6 No audio heard (2)
7 No audio heard (3)
2-1. No Power (front LED failure to light up)
or no startup (front LED failure to turn red to green)
NO
↓
Yes
NO
↓
Yes
2-2. With [RF]signalinput No video onscreen(1)
↓
Yes
NO
↓
Yes
NO
↓
Yes
NO
↓
Yes
Are the DC/DC converter outputs and the output voltages
along the control lines as specified?
1) D5.1V_USB (IC9607)
2) D3.3V (IC9605)
3) D1.8V (IC9601)
4) CPU D1.0V (IC9604)
5) CORE D1.0V (IC9603)
6) D1.5V (IC9608)
7) BU+5V (IC9610)
8) BU+3.3V (IC9605)
9) BU1.0V (IC9609)
10) PNL+12V (60"/70":Q3804, 80":Q3801)
NO
Check the DC/DC converters and the
control lines. Replace defective parts as
required.
Check FFC cable, LCD controller (incl.
panel) and their peripheral circuits.
No video in the UHF/VHF reception
Are the wire harnesses and other cables properly
connected in the set?
Reconnect the wire harnesses and other cables
properly in the set.
Are the PS_ON and PANEL_EN signals both
about 3.3V?
PS_ON:Q9607(G), PNL_EN:Q3803(G)[60"/70"]
Q3802(G)[80"]
Check the PS_ON and PANEL_EN signal line.
Is there IF output from the tuner
pin(6,7,8,9) of TU1102 as specified ? Check TU1102 and its peripheral circuits.
Is there IF input at pin K1 & K2 of IC3301 ? Check the circuit between TU1102 &
IC3301.
Are there the signal outputs (pin of IC3301
to SC 3801) ? Check IC3301 and its peripheral circuit to
SC3801