Sony Walkman MZ-R900, Service Manual

Page: 17 / 50

17
MZ-R900
• Setting method of NV reset
1. Select the manual mode of the test mode, and set item number
021NV Reset (see page 13).
2. Press the X key.
3. Press the X key once more.
4. Press the x key to quit the manual mode, and activate the
test mode (display check mode).
• Change of Adjusted Values
On the set having the microcomputer version 1.000, some adjusted
values were set in the manual mode at the shipment, but these data
will be cleared when the NV is reset. Therefore, on the set having
the microcomputer version 1.000, modify the adjusted values
through the following procedure immediately after the NV was
reset.
1. Item numbers in which the adjusted values are to be modified
Item number 832
Item number 862
Item number 871
Item number 872
2. Adjusted values modifying procedure
1) Select the manual mode of the test mode, and set item number
832 (see page 13).
2) Adjust with the
[VOL+]
key (adjusted value up) or
[VOL--]
key (adjusted value down) so that the adjusted value becomes
E4.
3) Press the
X
key to write the adjusted value.
4) Select the manual mode of the test mode, and set item number
862 (see page 13).
5) Adjust with the
[VOL+]
key (adjusted value up) or
[VOL--]
key (adjusted value down) so that the adjusted value becomes
01.
6) Press the X key to write the adjusted value.
832
Pw-T W **
Remote commander LCD display
**
:Adjusted value
SECTION 5
ELECTRICAL ADJUSTMENTS
Outline
• In this set, automatic adjustment of CD and MO can be per-
formed by entering the test mode (see page 12).
However, before starting automatic adjustment, the memory
clear, power supply adjustment, and laser power check must be
performed in the manual mode.
• A key having no particular description in the text, indicates a
set key.
• For the LCD display, the LCD on the remote commander is
shown, but the contents of LCD display on the set are same.
Precautions for Adjustment
1. Adjustment must be done in the test mode only.
After adjusting, release the test mode.
2. Use the following tools and measuring instruments.
• Test CD disc TDYS-1
(Part No. : 4-963-646-01)
• SONY MO disc available on the market
• Digital voltmeter
• Laser power meter
LPM-8001
(Part No. : J-2501-046-A)
• Thermometer (using the Temperature Correction)
3. Unless specified otherwise, supply DC 3V from the DC IN
3V jack (J601).
4. Switch position
SYNCHRO REC switch .............................. OFF
HOLD switch ............................................... OFF
Adjustment Sequence
1. NV Reset (Memory clear)
Manual Mode
r
2. Power Supply Manual Adjustment
Overall Mode
r
3. Temperature Correction (item number: 014)
r
Manual Mode
4. Laser Power Check
r
5. Electrical offset Adjustment
Caution: This adjustment must be made with
no disc loaded.
r
Overall Mode
6. CD Overall Adjustment
r
7. MO Overall Adjustment
r
Manual Mode
8. RESUME Clear
NV Reset
Caution: On the set having the microcomputer version 1.000,
some adjusted values were set in the manual mode at
the shipment, but these data will be cleared when the
NV is reset. Therefore, on the set having the micro-
computer version 1.000, change the adjusted values
following the Change of Adjusted Values immediately
after the NV was reset.














021
Res***
021
Reset!
Remote commander LCD display
NV reset (after several seconds)









021
ResNV CC
Remote commander LCD display
021
ResOK?
Remote Commander LCD display
862
V1dat **
Remote commander LCD display
**
:Adjusted value