Filter
Top Products
Chapter 3 - Troubleshooting
CTV-68 18
FIGURE 3-6
DIAGNOSTICS HISTORY PAGE
Backlight Issues
Under normal circumstances, any failures in the backlighting system will
cause the unit to shut down. If one or more of the fluorescent backlights
fails to turn on, or if the high voltage inverter circuit fails to turn on, the unit
will shut down and the standby LED will blink in groups of 6.
The first step to determine the cause of the failure is to observe the screen
of the television when it is first turned on. If the backlights turn on before
the shutdown, it is likely that one of the lamps has failed to turn on and the
LCD panel must be replaced.
If the backlights do not turn on, the high voltage inverter did not start and,
depending on the method of generating high voltage, replacement of the
power supply or inverter board is necessary.
No Backlight, No Shutdown
It is possible for a symptom of no backlighting to occur that does not
cause the television to go into protective shutdown. Dynamic dimming
control of the backlights is performed by monitoring information from the
TCON board. This is in the form of data and determines the brightness
level of the backlights based on video content.
If the TCON fails to process the RGB video data, or if the dimmer data line
fails, the backlights will not turn on. Audio will be present if the selected
input has it available. The television will remain on indefinitely with the
green Power LED lit. If the TCON is available, it can be replaced to resolve
the issue. If not, the LCD panel must be replaced.
Diagnostics History
Figure 3-6 illustrates an example of the diagnostics history page. Entry to
this page is achieved while the television is powered down and pressing
the following buttons on the remote commander: “DISPLAY”, “5”, “VOL –“,
“POWER”.
This feature is useful for failures which are intermittent or when the customer
is not sure what is causing the television to shut down sometimes. Once a
corrective action is determined the error events should be cleared to zero.
This is accomplished by pressing the “8” key followed by the “0” key on
the remote commander.
ERROR BLINK COUNT
EVENT COUNT
OPERATING
HOURS
NOT USED
NOT USED
NOT USED
NOT USED