Samsung ST436WMX/GAP Service Manual page 46

Troubleshooting
6-5 Digital Board Troubleshooting
1. PW364 Input Clock
1) MCKEXT
Check ICD115(ICS502) pin 5.
Power on: MCKEXT = 97.5 MHz
Standby: MCKEXT = 48.75 MHz
2) MCKEXT, DCKEXT
Check ICD125(ICS502) pin 5. DCKEXT=65MHz
3) VCLK
Check ICD301(SDA9400) pin 26. VCLK=27MHz
4) GCLK
Check ICD105(AD9884) pin 115 (TP160).
GCLK is differently seen according to PC input signal format(VGA,SVGA,XGA).
GCLK=15MHz ~ 50MHz (This value is apparently half of the clock frequency of the relevant
PC input signal format.
2. VPC3230
- Check power is supplied (5V, 3.3V).
- Check Reset (pin 15) is high.
- Check I2C-bus (pins 13, 14).
- Check the signal input to Y signal (pin 72), C signal (pin 71), PLL DVD-Y signal (pin 2).
- Check the output clocks LLC1 (pin 28), LLC2 (pin 27). (LLC1 = 13.5 MHz, LLC2 = 27 MHZ)
- Check the output H sync (pin 56) and check V sync (pin 57) is output.
- Check output digital data.
3. CIP3250
- Check power is supplied (5V, 3.3V).
- Check Reset(pin 55) is high.
- Check I2C-bus (pins 31, 32)
- Check the sampling clock (13.5 MHz) is input to pin 54.
- Check input digital data.
- Check PIP signal input.
- Check pin 61 (PIP OFF: Low, PIP ON: Some section is High like H sync)
- Check output digital data.
4. SDA9400
- Check power is supplied (3.3V)
- Check Reset(pin 30) is high.
- Check I2C-bus (pins 20, 21)
- Check clock is input. (pins 28, 54: 27 MHz. pin 29: 13.5 MHz)
- Check digital data input.
- Check the input H sync (pin 23) = 15.75 KHz, V sync (pin 22)= 60 Hz
- Check digital data output.
- Check the output H sync (pin 60)= 31.5 KHz, V sync (pin 61) = 60 Hz, VCLK (pin 26) = 27 MHz
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