Troubleshooting For Common Use - RCA 50LB45RQ Service Manual

Note: Before opening the cabinet and working on the repairs, please read the troubleshooting and Q&A attached in the
user's manual, which has covered most of the problems caused by unproper using or settings to the TV set. If that does not
work, please carry out the easy troubleshooting before checking or replacing the main parts of the television. The
troubleshooting guides given below base on the situation in which the TV's functions are set and used properly.
Plus, if the easy troubleshooting can not help, please work on the repairing according to the procedures given in chapter 5,
Exception Handles.
4.1 Troubleshooting for Common Use
TV can not be turned on
• Check the connection and condition of wires and inlets that relate to power board, including the AC power inlet, the
power incoming wire, wires between power board and mainboard, etc.
o Check the diagram arround power board to see If there exists a short circuit or creepage.
• The power board may be bad. Please change the board for testing. If it cannot help, refer to the chapter 5 for more
intensive information.
• In addition, the malfunction of LCD panel can cause failure of power on. Please refer to 4.2 Troubleshooting for Displaying
for more information.
Auto turning off
o Check the sleep timer setting.
• Check the surrounding diagram of power board. The problem is most possibly caused by short circuit or wire breakage,
because this kind of malfunctions can cause excessive current, which will make the power board startup self-protection.
The screen goes black after a shorting blink
e If the TV screen can not display after the blink, that means the panel or other parts of equipment is broken (most likely by
unproper input voltage). Ensure the input voltage of every component, and then check the part that is suspected damaged.
o If this problem occurs repeatedly, check the surrounding diagram and connections of panel inverter board. Also, the
blacklight unit and LCD lamps should be checked out.
There exists afterimages after power off
• If the panel can work normally at the other time, it may be caused by bad mainboard. Upgrade to the latest software first,
if that does not work, attempt to change the mainboard.
There exists squeak when TV is working
e IListen to the squeak carefully to make sure where the noise comes from. If it is from speakers, the voice may be caused by
bad speakers. Change them for a try..
• If the noise comes from the inner parts of cabinet, it may be produced by abnormal AC current in power board. Change the
board and check its surrounding circuits for a try.
• Check the routing of wires inside the cabinet to suppress interference.
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