I Power Supply (+5.2)


Make sure that connectors CN1 and CN4 of the power

supply board are firmly connected to CN11 and CN10

of the CPU board, respectively. Note that the Analog

ground path (AG) and Digital ground path (DG) of the

power supply board are electrically indepent of the


1, Turn the S-550 on.

Connect a voltmeter across TP +5(+5.2) and TPDG

of the power supply board.

3. Adjust VR1 of power supply board for +5.5V

reading. If VR1 fails to adjust, refer to the NOTE


NOTE:With products SN below 841699

If VR1 cannot bring the TP+5V to +5.2V, first

check RE for value.

Replace with 30k if the existing value is 27k .

All the products SN 841600 and up have 30k



udio Stage

Turn the S-550 off.

Connect the S-550 to an oscilloscope. Turn the

hope on.

Holding down 1 button, turn the S-550 on...

keep 1 button until the CRT displays "Please

nsert System Disk".

Insert the utility disk into the disk slot.

When the first access to the disk is complete, press

, and then ~MENU . The utility menu is

from the disk and written into internal


ect "Sampling" from the screen using the cursor

ons and press EXCUTE .

nnect INPUT jack to an audio generator and

y a 3Vpp, 1kHz sine signal.select

LINE using LINE/MIC button. Set REC

EL to MAX.

ect the scope to TPDA (DAC OUT) withground

at TPAG (analog ground).