Sharp LC-50U35T Service Manual page 33

No video at UHF/VHF and digital broadcast signal reception
Is the specified TV signal selected on the input select menu
screen?
Are there the IF signal at input pins(P6/P7)(TUN_IFN/P) of
IC3303(CPU)?
YES
Is the T-CON PWB connected?
V_LOCKN pin(26) of SC3802 become Low if there is no prob-
lem in the connection.
YES
Are the V-By-One HS signal input to the pin of SC3802?
V_VBO_TX_1+/-(23/24pin), V_VBO_TX_2+/-(20/21pin),
V_VBO_TX_3+/-(17/18pin),
V_VBO_TX_4+/-(14/15pin), V_VBO_TX_5+/-(11/12pin),
V_VBO_TX_6+/-(8/9pin), etc
YES
Check the panel module and harness.
No video (5)
NO Check the IF signal line between IC3303 and TU1105, and their
peripheral circuits.
Check the Tuner I2C lines.
TU1105:pin(10)(TUN_SCL), pin(11)(TUN_SDA)
IC3303:pin(E18), pin(F18)
Check the T-CON PWB and harness.
NO
Check IC3303 and SC3802 and their peripheral circuits in Main
PWB.
Check IC3303 and its peripheral circuits.(IC3501/IC3502/IC3503,
etc.)
NO
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LC50/58/65U35T