Jvc TDW 315 TN Service Manual

Page 2

TD-W315TN C/J
TD-W31GBK WE/EN/GlU/DT

I Safety Precautios

1. The design this product contains special hardware and many circuits and components specially for safety purposes. For continued
protection. no changes should be made to the original design unless authorized in writing by the manufacturer. Replacement parts
must be identical to those used in the original circuits. Service should be perlormed by qualified personnel only.

2. Alterations of the design or circuitry of the product should not be made. Any design alterations of the product should not be made.
Any design alterations or additions will void the manufacture's warranty and will further relieve the manufacture of responsibility for
personal injury or property damage resulting therefrom.

3. Many electrical and mechanical parts in the product have special safety - related characteristics. These characteristics are often
not evident from visual inspection nor can the protection afforded by them necessarily be obtained by using replacement
components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics aretidentified
in the parts list of service manual. Electrical components having such features are identified by shading and( A )0n the schematic
diagram and by ( A ) on the pans list in the service manual. The use of a substitute replacement which does not have the same
safety characteristics as the recommended replacement part shown in the parts list of service manual may create shock. fire. or
other hazards,

4. The leads in the products are routed and dressed with ties. clamps . tubings. barriers and the like to be separated from live parts.
high temperature parts. mpving parts and or sharp edges for the prevention of electric shock and fire hazard. When service is
required. the original lead routing and dress should be observed. and it should be confirmed that they have been returned to normal.
after reassembling.

5. Leakage current check (Electrical shock hazard testing)

After re - assembling the product, always perform an isolation check on the exposed metal pans of the product (antenna

terminals. knobs. metal cabinet. screw heads. headphone jack. control shafts. etc.) to be sure the product is safe to operate without

danger of electrical shock. Do not use a line isolation transformer during this check.

~ Plug the AC line cord directly into the AC outlet. using a"Leakage current tester". measure the leakage current from each exposed
metal part of the cabinet. particularly any exposed metal part having a return path to the chassis. to a known good earth ground.

Any leakage current must not exposeed 0.5mA AC(r.m.s.)

AC VOLTMETER
. Alternate check method 2 (Having 1000 ohms/volt,
or more sensitivity.)
Plug the AC line cord directly into the AC outlet. Use an AC

. . . . ~ 3 (I
voltmeter havmg 1.000 ohms per volt or more sensItIVIty in the 0.15 At: TYPE
following manner. Connect a 1.500 ohms 10W resistor paralleled by ya
a 0,155 a F AC type capacitor between an exposed metal part and P15 this probe
on each exposed
a known good earth ground. Measure the AC voltage across the 1500 n 10 W metal part.

resistor With the AC voltmeter, Move the resistor connection to each Good earth ground
exposed metal part. particularly any exposed metal part having a return path to the chassis. and measure the AC voltage across
the resistor. Now. reverse the plug in the AC outlet and repeat each measurement. Any voltage measured must not exceed 0.75V

AC(r.m.s.).This corresponds to 0.5mA AC(r.m.s.).

0 Warning

1. This equipment has been designed and manufactured to meet international safety standards.

2. It is the legal responsibility of the repairer to ensure that these safety standards are maintaintaind,
3. Repairs must be made in accordance with the relevant safety standards.

4. It is essential that safety critical components are replaced by approved parts.

5, If mains voltage selector is provided. check setting for local voltage.

2 (N0. 4353)

Page 18

TD-W315TN cu
TD-W31GBK Als/E/EN/GIU/u'l'

18 (No.

0 Electrical Adjustment Procedure

Adjust LG151 and L6251 to minimize
respective voltages of CNGSS (PlN3-5) at Lch

and (PINS-4) at Rch.

Item Check and Adjustment

1 Cheking input signal Output raise
DOLBY (Frequency, level) value,devtatlon value
circuit Signal input: LINE lN Cal.level: 400Hz. 1kHz. cal. - 40dB +57 dB i 2 dB
(Rea-mode - 8st 0%: B skHz, Cal. - zode +3.5dB : 1.5 dB

. 0t tt lTP:ICDSS Kt .
(B'As CUT) pi: p ermm @ ® 1kHz. Cal. OdB 0 dB : 3.st
1kHz, Cal. - 40 +162 dB ii dB
Y
DOLE C 5kHz, Cal. - 20 +2.9 dB : 2.5 dB
(Rec)
1kHz, Cal. OdB 0 dB 1 1 dB
Item Conditions Adjustment and Confirmation Standard Adjusting

*2 Play back Test tape Flay back VTT724, then confirm that the level LINE OUT Deck
level adjust- VTT724: 1kHz at LINE OUT is - 7.5 ass i 0.5 dB. -8dB:(1)'§dB L: VRA15
ment Adjust VRA15 VRA25 and VFiA11 VRA21 so PHONES'Out RzVRA25

- .5 B . M

that LlNE OUT level becomes 7 d s 44st 4.12.318 Deck
- - L : VRA11
R :VRA21

*3 Playback Test tape Play back TMT735 test tape, and adjust with 12.5kHz Deck
frequency TMT735:1kHz/12.5kHz VRAt 6, VRA26 (deck and VRA12, VRA22 as reference, L: VRA16
response VTl739 :1kHz/63Hz (deckE so that deviation of 12.5 kHz to that of 0.5 i 0.5 dB at R: VRAZG
adjustment 1 kHz is 0.5 i 0.5 dB. 1kHz Deck R

Then, play back Vi I739 test tape to confirm 63Hz(check)z L: VRA12
that deviation of 63 Hz to 1kHz is +2 : 3 dB. +2 1- adB R: VFtA22

*4 Bias Frequency counter Connect a frequency counter to the CNG85 95 kHz 1' 1 Deck
frequency TP :CNGBS and adjust LE851 so that the counter reads 95 kHz LE851
adjustment kHz.

*5 Slave DC.Voitmeter This step must be performed after the bias Deck
oscillation TP:CN685 frequency adjustment. L : Lat 51
(HX PRO) Load a metal tape and set the deck to the Ft : LGZS1
adjustment recording mode.

4353)