Failure phenomena

Reasons for failure

Failure analysis and solutions

1.The whole screen doesn¡¯t light or appears pane

•  if the controlling host machine has started
•  if the communication line is well  plugged
•  if the sending card is well plugged
•  if the data line between the multi-media card and collecting card and sending card is well connected
•   wrong switch location of receiving card JP1 or JP2

•  open the host machine
•  plug well the communication line
•  replugged the sending card
•  connect the data line between the multi-media card and collecting card and sending card well
•  adjust well the switch location of JP1 and JP2

2.Every time when starting LED studio, there is a hint :controlling system cannot be found

The signal collecting line between COM port to sending card doesn¡¯t connect or the COM port of the computer is broken

Connect data line well or change computer

3 .in the whole screen, the data glitter or keep lighting every 16 lines

Check the settings in LED studio

Open LED studio, open the debugging ?hardware setting password 168 system setting set the row sequence as +0 or +1

4 .whole screen pictures tingling or fringing

•  Check the communication line between the computer and large screen
•  Check the DVI line between multi-media card and sending card
•  sending card is broken

•  replug or change the communication line
•  strengthen DVI line plug
•  change sending card

Failure phenomena

Reason for failures

Failure analysis and solutions

1.One unit panel do not light

1 .if +5V electricity  or GND supply
2 .if +5V and GND are short circuit
3 .if the OE signals of 138 no. 5 leg exists
4 .if the OE signals which connected with 245  are normal (open circuit or short circuit)

•  supply +5V electricity or GND
•  cut the short-circuit part
•  supply OE signal . connect the open circuit part cut the short-circuit part

2.One unit panel upper half or lower half do not light or display unnormally

1.if the 5 th leg of OE signal of 138 exists .
2 .if the no. 11 and 12 leg signals of 74HC595 are normal(SCLK,RCK).
3.if the connected OE signals are normal; open circuit or short circuit.
4.double row pins and the signal of  SCLK ,RCK connected with 245 are normal .open circuit or short circuit.

•  connect OE signal
•  connect SCLK.RCK signal well
•  connect the open circuit part cut the short-circuit part
•  connect the open circuit part cut the short-circuit part

3.One row of one unit panel  or row of onecorresponding module do not light or display unnormally

1.check if the pin of corresponding module row signal is cold welded or miss welding
2. check if the row signal and TIP127 or 4953 corresponding pins are cut off or short circuit with other signals
3.check if the up-and-down pull resistance of row signal  do not weld or miss welding
4. if the 74HC138 output row signal and corresponding TIP127 or 4953 are cut off or short circuit with other signals

•Weld well for the cold welding and miss welding part
•  connect the open circuit part cut the short-circuit part
•  weld the not welding part, weld well of the miss welding part
•  connect well the open circuit part,cut the short circuit part

4.One unit panel has two rows lighting at the same time .when displaying words, one row is normal, another row keeps lighting

1.Check if the module corresponding  two rows of signals are short circuit
2.Check if the output leg of 138. up-and-down pull resistance and module pins and the output leg of TIP127 are shot circuit

•  cut the short circuit part
•  cut the short circuit part

5.upper part or lower part, red or green don¡¯t light or not display normally

1.check if the input row niddle feet are normal or short circuit with GND.+5V
2.check if the signals from input row niddles to 245 are normal short circuit or open circuit.
3.IC245 is broken

•  connect the open circuit part
•  cut the short-circuit part
•  change IC