Motorola tm 706 s service manual

Page 1

automotive stereo tape player

MOTOROLA

automotive stereo tape player

GENERAL INFORMATION

Universal 8 track car stereo tape
cartridge player designed for 12
volt negative ground installations.

Model KM13S is a rear door speaker
kit for this model.

WARRANTY SERVICE
STATION PROCEDURE

1, A Motorola Branded Modelis one
that has the Motorola name and is
distributed to dealers through the
Motorola Distributors.

2. This model is guaranteed for all
parts and labor, including removal
and re-installation (R & R) for a
period of one (I) year from the date
of purchase. The following repairs
are not covered under this guar-
antee: the elimination of motor
noise. tire static, electrical inter-
ference and faulty installation.
Charges for these repairs are to be
paid by the customer,

3. Before performing a guarantee
repair on a Motorola Branded Auto
Tape Player, you must first receive

4. To obtain your labor allowance
for the servicing of the customers
in-guarantee set, fill inthe Motorola
Guarantee Labor Claim, Part No,
68P60016A30. If you perform a
R S: R service, you are entitled to
the R Br R allowance. If you only
repair the tape player without R & R
service, you are entitledto the labor
allowance. However, ifyouperform
both R & R and the repair, then be
sure to indicate both on your claim
form for both allowances, After the
form has been filled in, mail the
pink and green copies to your
Motorola Distributor for payment.
The yellow copy is to be retained in
the service station file,

MANUAL 68P64994A60

MODEL TM706S, KMI 35

service manual

5, Defective parts for guarantee re-
pairs made are to be sent to your
Motorola Distributor for free re-
placement supported with the defec-
tive parts return tag, Part Number
541359 180 8.

6. Only those service stations auth-
orized by their Motorola Distributor
can perform repairs within the
guarantee period on a no-charge
basis to the customer. If you are
not an Authorized Motorola Auto
Radio Service Station and you are
interested in handling this service,
please contact your Motorola Dis-
tributor for complete details.

tape cartridge will now play, in suc-
cession, all four programs. Adjust
volume, tone and balance as re-
quired.

CAUTION: The tape cartridge
should always be pulled out com-
pletely or approximately I from
the seated (play) position before
leaving car.

TAPE CARTRIDGE CARE

To assure maximum life and noise
free operation, tapes should be
stored ina cool, clean and dry place,
out of the rays of the sun and with
the open (tape) end down.

SERVICE NOTES

1. FOLARITY - WHEN SERVICING
THIS UNIT, THE A LEAD MUST
BE CONNECTED TO THE POSITIVE
SIDE OF POWER SOURCE. IF CON-
NECTED OTHERWISE, UNIT WILL
NOT OPERATE AND DAMAGE TO
COMPONENTS MAY RESULT.

2. POWER SUPPLY REQUIRE-
MENTS - It is preferable to use a
storage battery (without a battery
charger) in place of a battery elim-
inator, If a battery eliminator is
used, it must be well filtered and
regulated.

3. OUTPUT LOAD - Always oper-
ate this unit with an output load
across each of the two channels;
either 8 ohm speakers or 8 ohm, 5
watt resistive loads can be used.

4, TRANSISTOR REPLACEMENT -
When replacing a transistor other
than a power or regulator transis-
tor, grasp the transistor leads be-
tween transistor body and plated
chassis board with a pair of long
nose pliers to prevent excessive
heating of transistor body during
soldering operation,

g ,8 Te Cgstgffrsguaraxfefieds; OPERATING INSTRUCTIONS
a 2 Vice 9° 5 - . e 115 a 3 1° an 5. POWER AND REGULATOR
g x model information on the booklet OPERATION TRANSISTOR REPLACEMENT _
g _ must be filled in by the selling When replacing apower or regula-
g 3 dealer at the time of retail sale. The TO PLAY TAPES - Turn unit on by tor transistor be sure to'
0 E Customers Guarantee and Service rotating the on-off and volume knob '
_. . ,
g E Booklet must show that the tape to the right. Select atape cartridge A. Use the transistor specified
2 !- player is withintbe guarantee period and insert it - label side up and open in the Replacement Parts List.
2 d to be repaired under the Motorola end first - into the tape slot. Push
8 Guarantee. the cartridge in until it isTfirigifiy B, Coat both sides of transistor
2 seated. (THIS IS IMPORTAN " e insulator with DC4 grease

(Motorola Part No. Ill/1490487)
to insure proper heat dissipation.
C. Securely and evenly tighten
the transistor mounting screws.

6. GAINING ACCESS TO THE
PLATED BOARDS - Remove top and
bottom covers and refer to photo on
page 5.

Tape Pre-Amp Plated Board - To
remove this board for servicing.
merely unsolder the chassis ground
lead (see photo). bend the copper
retaining clip and lift up the chassis
to a more serviceable position.

MOTOROLA INC.

9401 WEST GRAND AVENUE. FRANKLIN PARK, ILLINOIS

PART NO. 68P64994A60 2-67 PRICE 35 CENTS COPYRIGHT 1967 BY MOTOROLA INC. - PRINTED IN U.S.A.

Page 2

Audio AInplifier Plated Board - To
remove the board for servicing, re-
move the 2 screws from the mount-
ing bracket, then remove the mount-
ing bracket.

7. TAPE CARTRIDGES - Before
servicing the tape player portion of
this unit, always check for the pos-
sibility of a defective pre-recorded
tape cartridge, particularily if one
is returned with the unit. This
should be done by substituting the
tape cartridge with one thatis known
to be good,

8. TAPE HEAD AND CAPSTAN
CLEANING - One major cause of
improper tape player operation is
oxide build-up on the head and cap-
stan. During normal operation,
some iron oxide particules are
loosened from the tape and build up.
This accumulation of oxide can cause
poor playback and tape to move up
and down. The head and capstan
should be cleaned whenever the unit
is serviced and this can be done
either in the car or on the service
bench. To clean the head and capstan,
use a cotton swab moistened with
head cleaner or isopropyl alcohol,
then wipe dry.

critical; for this reason, replace-
ment heads are supplied already
secured to their mounting bracket
and positioned correctly at the fac-
tory. When replacing a head, re-
member to replace it as an assem-
bly, that is, remove the defective
head and bracket and replace it with
the new head and bracket assembly.

if for some reason the location of
the head has changed (due to aloose
mounting screw, etc.), position it as
shown in Head Positioning Adjust-
ment".

ADJUSTMENTS

Head adjustments are normally re-
quired for cases of cross-talk, loss
of frequency response and noise or
if the head has been replaced.

A suitable test tape should be used
for the azimuth and height adjust-
ments. Motorola has a suitable test
tape cartridge available for the field
under Part Number 99P43309A01.
Instructions in the form ofalabel on
the cartridge are included.

Connect 8 ohm loads (either
speakers or resistors) across the

CAPSIAN SHAH

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TAPE HEAD & CAPSTAN CLEANING

9. HEAD DEMAGNETIZING - Do not
use magnetized screwdrivers and
wrenches near the head since these
can magnetize the head. The head
may also, after a long periodof time,
acquire some residual magnetism,
A head that is magnetized will show
a definite loss of high frequency re-
sponse and an increase in noise
level. Use a commercially available
head demagnetizer, following in-
structions included with the unit to
demagnetize the head.

10. HEAD REPLACEMENT - The
location of the tape headwith respect
to its mounting bracket is very

2

output of both channels and set tone
control to treble (maximum clock-
wise). Use an oscilloscope or AC
output meter and a 1/16" Allen
wrench for azimuth and height ad-
justments (Motorola Part Number
66P40059A32).

HElGHT

This is an adjustment to move the
tape head up or down so that it can
be positioned exactly in line withthe
pre-recorded information on the
tape, Misadjustment of this screw
would cause cross-talk and/or poor
separation.

With the Motorola testtape. proceed
as follows:

1. Remove top cover and make sure
output loads are connected across
each channel.

2. Insert test tape cartridge into
tape slot and position head to tracks
2 and 6.

3. Set balance control for maximum
output from left channel.

4. Connect scope (or VTVM) across
left channel output - (track 2 in-
formation - ch will be presented).
Adjust height adjusting screw for a
null. The reason for the null is that
the ch information is recorded not
on track .2 but on the guard bands
adjacent to track 2. This adjustment
will minimize cross-talk.

5. Azimuth - Connect scope or
VTVM across the output of the right
channel and adjust balance control
for maximum right channel output -
(track 6 information - 8Kc will be
presented). Adjust azimuth ad-
justing screw for maximum output.

Misadjustment of this screw would
cause poor highfrequency response.

milligram mm

/
50 W P IVOY

HEAD TENSION

ADJUSTING

SCREW

AZIMUTH

ADJUSYING

SCREW

HEAD MOUNTING

SCREW
(LOOSE?! TD
REPOSITIDN HEAD)

HEAD ADJUSTMENTS

6. Repeat Steps #4 and #5 to opti-
mize these adjustments, then cement

adjusting screws in place with
glyptal or other non-hardening
cement,

The next two adjustments are not
normally required except when the
head has been replaced or tampered
with.

HEAD TENSION ADJUSTMENT

This adjustment will have to be made
if the head assembly has been re-
placed. Adjust the screw so that
there is 1/4 betweenthe bottomflat
of the screw head and the head
mounting bracket with head in its
lowest position (tracks 4 and 8).
Apply glyptal to the screw from the
bottom.