Service manual

ManualsBrandsSharp ManualsComputer equipmentLL-153A

15” LCD Color Monitor Sharp LL-153A

31

4. U4-DATA OUTPUT

8.2.2 Keypad Board

Measured DCLK(pin 65,66 from U401)

DVS, DHS (pin 63,64 from U401 )

Is the waveform ok?

DCLK around 48 MHZ , DVS=60.09Hz , DHS around 80

KHz ?(refer to input signal=640x480@60 Hz 31k, and

LED is Green)

OK

Replace TSUM13AK (U401) or

replace Main board.

Check TSUM13AK(U401)

Signal output (PIN105-114, 118-127)

Is the waveform ok ?

OK

If Main Board being replace, please

do the DDC – content reprogrammed

OK

NG , no transition

OSD is unstable or not working

Is Key Pad Board connecting normally?

Connect Key Pad Board

Is Button Switch normally?

Replace Button Switch

Y

N

N

Is Key Pad Board normally?

Replace Key Pad Board

Y

N

Y

Check main board