Jvc RCX 740 Service Manual

Page 1

JVB
SERVICE MANUAL

RC - X74OB /EN/G/Gi

RC -X740 B/E/EN/G/Gl

riflfimg'fi

DIGITAL AUDIO
Area Suffix

Note

The RC - x740 B/E/EN/G/Gl ls basically the same as 5"

the RC - x540 B/E/ENIG/Gl (Excluding the cassette mechanism ) EN --------------------------- North Europe

Thertore. please refer to the service manual (No.1929 ) for the G Germany

Rc - X740 B/E/EN/G/GI for details of the RC - X540 BlE/EN/G/GI

other than the Instructions. Troubleshootlng of CD part etc. 3' " """ "my
1, Safety Precautions ...................................... Page 2 8. Block Diagram ............................
2. Safety Precaution about RC - X740 ---------------------- a 9. Wiring Connections ------------------------------------------ 30
3. lnstructions( Refer to RC - X540) -------------------------- 6 10. Standard Schematic Diagram ---------------------------- 31
4. Location of Main Parts ~~~~~~~~~~~~~~~~~~~~ ---6 11. Location of RC. Board Parts ------------------------------ 37
5. Removal of Main Parts -7 12. Electrical Parts List ----------------------------------------- 41
6. Main Adjustment --------------------------------- ~16 13. illustration of Packing and Parts List

7. Analytic Drawing and Parts List ---------------------------- 22

No. 1931
May 1995

Page 2

RC - X740 B/E/EN/G/Gl

__..t

I Cassette / Recorder Deck Sections

Item Conditions Adjustment & Confirmation Methods Stand. values Adjust
Head azimuth . Test tape * Adjust the head azimuth screw only when the head Within 2dB of Head
adjustment : VTT703L(10kHz) is replaced. the peak level azimth
(A. B mechanism) - Output terminal ®Playback test tape VTT703L( 10kHz) . Minimum adjusting
for measurement ®Adjust the head azimuth so that the phase phase screw
: Headphone difference is minimum (Within 2dB of the peak difference
- Input terminal for level of play output.) After adjustment apply the
measurement screw locking adhesive to the head azimuth screw
: CN301 more than a half arund the screw head.
Tape speed - Tast tape (DWhen playing test tape VTT712 (3kHz). - Tape speed VRA61
adjustment and : VTT712 (3kHz) ®Adjust VRA61 so that the frequency counter : 2990Hz
wow &Flutter - Output terminal reading is 2990Hz ~3010Hz . ~3010Hz
checking for measurement ® Wow &Flutter should be less than 0.38%(JIS
(A, B mechanism) : Headphone UNWTD) Wow &Flutter
: Less than
0.38%(JIS
UNWTD)
Play back output - Tast tape @When Playback the test tape VTT724 (1kHz) . - 26dB :
level checking : VTT724 (1 kHz) the output level at headphone is - 26dB : 3dB 3dB
(A, B mechanism) -Output terminal at 1kHz.
for measurement @Deviation L and R 2 less than adB
: Headphone
Playback o Tast tape When playback the test tape VTT736, response 63Hz and
frequency : VTT736 should be - 3dB : 4dB at SSH: and 1kHz, +1dB : 1kHz
response -Output terminal 4dB at 10kHz and 1kHz with respect to 1kHz. : .. 3GB :
checking for measurement 4dB
(A, B mechanism) : Headphone 10kHz and
1kHz
+1 dB : 4dB
Record / - Reference @Record and playback the 1kHz reference
playback frequency frequency and 10kHz signal and check at
frequency : 1kHz, 10kHz treminal CN301.
response (Ref. - 20dB) @Adjust the VFtA41 so that record and playback VRA41
adjustment - Test tape : frequency response with 1kHz and 10kHz at + 1dB i 1dB
(A mechanism) A0224 CN301 is +1dB : 1dB
- Output terminal ®Comfirm that the frequency counter reading is 95.5kHz :
for measurement 95.5kHz i 3kHz. If the reading is out of this 3kHz LA341

:CN301

range, adjust LA341.

18 (No.1931)

Page 10

RC7X

RC - X740 B/E/EN/G/Gl

I Enclosure Assembly Part: Block Nam-5]

(No. 1931) 24