TOSHIBA SD-170EKB2
Service Manual

1-10

Trouble shooting chart

No video picture, no sound.
No video picture, no sound. Go

Check whether all the voltages from the power board to the decoder board are normal.

No Check the loaded circuit CVBS(R21 point) waveform

Yes

Check if the reset circuit consisting ofEC9, D1 and Q1 is normal (at a high level for tens of milliseconds, then constantly at 0V).

No

Change EC9, D1and Q1.

Yes No Check whether there is 27MHz signal output. Crystal oscillator Y1 and peripheral components are defected or eroded. Yes

27Mhz waveform

Check if there is 135MHz signal output on R2.

No

Check whether short-circuit or bad solder on U2,U4

SDRAM(R2 PCLK) waveform Yes No

Check if short-circuit and bad solder exist on Pin 151

No Check U1.

Yes Yes

Reconnect the component in