XL-DV50 (serv.man2) - Sharp Audio Service Manual (repair manual). Page 8

XL-DV50H

2 – 2

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

For obtaining each test mode, press the ON/STAND BY button, while
keeping pressing the following two buttons in the ordinary stand-by
mode (power off). In this case, the main unit buttons are valid. When
turning the POWER on with remote control buttons, test modes are not
obtained.

[Ordinary test mode]

[Self-diagnosis Test Mode]

Processes are different depending on destinations at initial settings.

1. Outline of tuner (radio) test mode

The tuner test mode is intended to store the adjustment and mea-
surement frequencies in the preset memory CH. When adjusting
the tuner section in the production line, adjusting personnel are not
required to set frequency.

2. Details of tuner test mode

Press the "TUNER(BAND)" and "VOLUME UP" buttons in POWER
OFF state and turn on the power by the use of "ON/STAND BY"
button to preset and store frequency for adjustment and measure-
ment of destination specified by the AREA terminal in the preset
memory CH. However, Ordinary 1 and Ordinary 2 are stored in the
destinations when the test mode is obtained. 

(As for frequencies to be preset and stored for each destination, refer
to item 3.)

The tuner test mode is started from preset No.1.

The operations of test mode are identical with the ordinary operations
of TUNER function. FUNCTION switching is invalid.

It is necessary to discard the content of preset memory when the tuner
test mode is ended; be sure to write "0000" or "1111" bits in the mem-
ory to be checked for judging memory error at initial setting and to ini-
tialize memory.

When the tuner test mode is obtained, the following display lights for
one second.

• The TUNER TEST 2 mode is obtained with >> + MEMORY/SET +

ON/STAND-BY. ->Turn off AC in the TEST 2 mode to restore the
initial state.

Turn off POWER to protect the memory of TEST 2 mode.

Turn off POWER again to obtain the ordinary operation while the
data is stored in the memory (besides TUNER).

If AC OFF state is maintained in this state for about 1/2 day, start is
executed in the initial state.

• To clear the whole memory, insert the AC cord, pressing MEM-

ORY/SET + PLAY.

3. Preset frequencies for various destinations

(random  preset memory)

• The slant line sections of the table store no memory.

When this test mode is obtained, the following display lights for one
second.

In this mode, volume is Volume -14 dB (STEP 23), FLAT AND X-BASS
ON, and start-up function to DVD/CD, respectively. The button opera-
tions in the test mode are the same as those of ordinary operation
except volume UP/DOWN.

1) The display is the same as that of ordinary operation except test

mode setting.

2) Unlike the ordinary state, the volume is controlled with the volume

UP/DOWN button in accordance with the following three steps.

Volume- 

∞ (STEP 0) <-> Volume-14 dB (STEP 23) <-> Volume-0

(STEP 30)

3) X-BASS is switched when button is pressed.

1. Tuner Test Mode (TEST 2)........................................................

TUNER(BAND) + DISC1

2. Electronic Volume Test Mode (TEST 3).....................................

TUNING DOWN + VOLUME UP

3. Timer Test Mode (TEST 4).......................................................

TUNING UP + DISC5

4. FL Test Mode (TEST 5)...........................................................

PRESET DOWN + VOLUME DOWN

5. DVD MECHANISM Aging Test Mode (TEST 8).........................

DVD/CD + Equalizer

1. Button input diagnosis test mode (TEST 6)...............................

PRESET UP + DISC5

1
2
3
4
5

FM STEREO

FM 87.5 MHz
FM108.0 MHz
FM 98.0 MHz
FM 90.0 MHz
FM106.0 MHz

6
7
8
9
10

AM

AM 530 kHz
AM1720 kHz
AM 990 kHz
AM 600 kHz
AM1400 kHz

16-35

——————

36
37
38
39
40

FM MONO

FM106.0 MHz
FM 90.0 MHz
FM 98.0 MHz
FM108.0 MHz
FM 87.5 MHz