Service manual of MT31AS
Many problems may cause the TV can't start up. Firstly
，
it's need to foreclose the possible bad
board
（
such as main board, key board, panel etc).We can do the right thing only if we find the bad
board. The main reasons such as: power supply abnormal, core voltage, DDR's reference voltage,
main program abnormal, MBOOT program abnormal, wrong panel parameter, EEPROM data
abnormal, bad Main IC and DDR etc. The print information will be useful to analyzing the
problems quickly recur to the serial interface tools.
6.2. Abnormal display
Check
each
DC-DC and there
terminal voltage
regulator unit.
DDR.
Abnormal
Ok
Both have
Check each
DC-
DC unit’s
outputs, and the
power supply of
Main IC and
DDR.
Check P_ON, DIM,
BL_ON.
Not work
Check 3.3VSTB and
12V/24V
Both
no
Check Power Unit
Only
has
3.3VSTB
Check Reset signal of Main IC
Check IIC bus signal. Try to cut off Turner
and AMP bus .Then start up.
Check Crystal
Check print information if necessary.
Check the Main IC’
periphery circuits
and the hole
between Main IC and
peripheral signals.
Change Main IC.
No
Normal
Normal
Normal
