XL-55 (serv.man22) - Sharp Audio Service Manual (repair manual). Page 10

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2. CD Test Mode (TEST 1)
In the CD test mode the operation of each step is enabled even when the LID-SW is off. However, if focus cannot be set in step 3
or any error processing is started, it is impossible to proceed to the next step. When the error processing is started, operations other
than termination of test mode by pressing the ON/STAND-BY button or return to the step 1 by pressing the STOP button are inhibited.

1. Step 1 Mode
When the CD test mode is turned on, the following indication lights, the processing (until turning-off of CD STB terminal of CD
initialization operation flow) is executed, and the next button input is waited.

After lighting for one second

If the following operation buttons are pressed in this state, the operation is performed as follows.

"ON/STAND-BY" ...... The test mode is turned off, the power is turned off, and the ordinary stand-by mode is set.
"FF/FWD" ................. After the pickup returns once to the innermost periphery, it slides toward the outer periphery while this

button is held down.

"REW/REV" .............. After the pickup returns once to the innermost periphery, it slides toward the inner periphery while this

button is pressed. However, if PU-IN is on, input is invalid.

"PLAY" ..................... Shift to step 2
"STOP" ..................... Invalid
"REC PAUSE" .......... Shift to step 5

The test mode applied to this microcomputer has three modes, namely ordinary test mode to be used for adjustment or
measurement, aging test mode to be used for aging test, and self-diagnosis test mode for self-inspection in case of final product
inspection.

To turn on the specific test mode, press the ON/STAND-BY button, holding down the following two buttons in the ordinary stand-
by mode (power off state). In this case only the main unit button is valid. Even when the ON/STAND-BY of remote control button
is set to on, the test mode is not turned on.
[Ordinary test mode]
1. CD  Test Mode (TEST 1)…………………… BASS/TREBLE + FF/FWD
2. Tuner Test Mode (TEST 2)………………… BASS/TREBLE + REW/REV
3. Electronic volume Test Mode (TEST 3)…… BASS/TREBLE + REC
4. Timer Test Mode (TEST 4)………………… MEMORY/SET + REC
5. LCD Test Mode (TEST 5)……………………MEMORY/SET + REW/REV

MEMORY/SET + PLAY

[Self-diagnosis Test Mode]

1.  Button input diagnosis test mode (TEST6).…

• Setting the Test Mode
Keeping the REW/REV button and BASS/TREBLE button
pressed, turn on POWER. Then, the frequency is initially set
in the memory as shown in Table. Call it with the PRESET
button to use it for adjustment and check of tuner circuit.

1

87.50 MHz

2

108.00 MHz

3

98.00 MHz

4

90.00 MHz

5

106.00 MHz

11~25

––––

6

531 kHz

7

1,602 kHz

8

990 kHz

9

603 kHz

10

1,404 kHz

26

106.00 MHz

27

90.00 MHz

28

98.00 MHz

29

108.00 MHz

30

87.50 MHz