Sharp LC-70EQ10U Service Manual page 118

LC-60/70EQ10U,SQ10U/15U/17U,TQ15U,UQ17U
No video at UHF/VHF broadcast signal reception
Is the specified TV signal selected on the input select menu screen?
Are there the IF signal at input pins(AT32/AU32)(TUN_IFN/P)
of IC3301(CPU)?
NO
Check the IF signal line between IC3301 and
TU1104, and their peripheral circuits.
Check the Tuner I2C lines.
TU1104:pin(5)(TUN_SCL), pin(4)(TUN_SDA)
IC3301:pin(V35), pin(V34)
YES
Is the T-CON PWB connected?
VBO_LOCKN (40pin) of SC3801 become Low if there is no problem in the connec-
tion.
YES
Are the V-By-One HS signal input to the pin of SC3801?
VBO_CN_TXA+/- (36/37pin), VBO_CN_TXB+/- (32/33pin),
VBO_CN_TXC+/- (28/29pin), VBO_CN_TXD+/- (24/25pin).
YES
Check the panel module and harness.
No video (5)
No video at digital broadcast signal reception
Are there the IF signal at input pins(AT32/AU32)(TUN_IFN/P) of
IC3301(CPU)?
Is there IF-AGC signal at input pin(12) of TU1104?
Check the IF signal line between IC3301 and
TU1104, and their peripheral circuits.
Check the IF-AGC line between pin(U35) of IC3301
and pin(12) of TU1104.
Check the Tuner I2C lines.
TU1104:pin(5)(TUN_SCL), pin(4)(TUN_SDA)
IC3301:pin(V35), pin(V34)
YES
NO Check the T-CON PWB and harness.
Check IC3301 and SC3801 and their peripheral cir-
cuits in Main PWB.
NO Check IC3301 and its peripheral circuits.
(IC3501/IC3502/IC3503/IC3504, etc.)
6 – 29
NO