Grundig POWERMAX Q2, Руководство по обслуживанию

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109
FAILURE/ERROR ANALYSES
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Sound available but no picture, and back-lights not illuminated
In the cases where audio is available yet the
back-lights are not lit, first of all, check the cable
and connector connections to the panel. After
the connection checks are completed, check
whether 12V is present on the 4th pin of the
chassis S900 connector. PSU must be changed
if 12V cannot be measured on this pin. If 12V
voltage is present, check the 13th pin of the
S900 connector on the chassis. If the BL_CTRL
signal is 0V on the 13th pin, it indicates that
there is a problem originating from software or
IC. If the voltage measured on this pin is 0V, for
test purposes connect 3.3V to the S900 con-
nector of the chassis PSU cable which is located
on the chassis side. If the TV does not operate,
then there may be a problem originating from
LED or driver. First replace the LED driver circuit
then the panel if the problem persists. If the TV
operates, increase the backlit to the maximum
and install a different version of software and
try again. To make sure that system works, turn
back light down to the lowest level and check. If
no problem occurs, submit TV.