Motorola p 6 mh service manual

Page 1

automotive MANUAL 68P43'IOIAI9

MOTOROLA P6MH

INTERNATIONAL
' HARVESTER 244708-R9I

stereo 8 track tape player

MOTOROLA

GENERAL INFORMATION

This model is designed for installa-
tion in the following International
Harvester vehicles: lOOOA-ISOOA,
CO-4000, Fleetstar, Loadstar,
Metro, R & V line, Scout.

WARRANTY SERVICE
STATION PROCEDURE

1. A defective in-guarantee player
must be accompaniedby the Custom-
er's Guarantee Policy Tag. This tag
must be properly filled"in by the
International Harvester dealer at
the time of the player purchase.
Accept as guarantee repairs only
those players within the 12 months
or 24,000 miles (whichever occurs
first) guarantee period. The re-
moval or re-installation of this
player is customarily performed by
the International Harvester dealer
and is not covered bythis guarantee.
Also, the removal of motor noise,

service manual

nan-charge basis to the customer. If
you are not already authorized as a
Motorola Auto Radio Service Station
and you are interested in handling
this service, please contact your

SERVICE NOTES
GENERAL SERVICE NOTES

3 I - ~ . , , I 1. POLARITY - WHEN SERVICING
5 E a: tire static, electrical interference 3:223:5013 Distributor for complete THIS UNIT, THE A LEAD MUST
g g 8 and faulty installations are not con- BE CONNECTED TO THE POSITIVE
E '; tsfiderfed as guarantee lretpadll: and); SIDE OF POWERSOURCE. IF CON-
a < -| ere ore, expenses re a e 0 513 NECTED OTHERWISE UNIT WILL
~o *f . n
3 '0 2 N services should be handled by the OPERATING INSTRUCTIONS NOT OPERATE AND DAMAGE TO
2 g g a dealer- OPERATION COMPONENTS MAY RESULT.
< I- E E _ I
2 O W 2. Fill in MotorolaGuarantee Labor .
2 oz: g Claim, Part Number 68P60016A30, :IO KAY TAPES Tu? m on by fiEifiIgERR .SUPPfLY bengE'
IE i and mail Green and Pink copies to: Farting a tape cartridge (label _ ls prerera e 0 use a
Z :I: Slde up and open end first) into the storage battery IWWhOUt 3 battery

automotive stereo 8 track tape player

MOTOROLA INC.

Motorola Guarantee Service
Motorola, Inc.

9401 West Grand Avenue
Franklin Park, Illinois.

3. The yellow copy of the Motorola
Guarantee Labor Claim is to be re-
tained by the authorized service
station for his files.

4. Defective parts for guarantee re-
pairs made on this model are to be
sent to your Motorola Distributor
for free replacement supportedwith
the defective parts return tag or
form which you are now using.

5. Only those service shops author-
ized by their Motorola Distributor
can perform guarantee repairs on a

tape slot. Push the cartridge in
until it is firmly seated. (THIS IS
IMPORTANT.) The tape cartridge
will now play, in succession, all
four channels. Adjust volume, tone
and balance as required.

CAUTION: The tape cartridge
should always be pulled out com-
pletely or approximately 1" from
the seated (play) position before
leaving car.

TAPE CARTRIDGE CARE

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

charger) in place of a battery elim-
inator, If a battery eliminator is
used, it must be well filtered and
regulated.

3. OUTPUT LDAD - 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 apower or regulator transistor,
grasp the transistor leads between
transistor body and plated chassis
board with a pair of long nose pliers
to prevent excessive heating oftran-
sistor body during soldering opera-
tion.

9401 WEST GRAND AVENUE, FRANKLIN PARK,
PRICE 35 CENTS

I L Ll N O | S
COPYRIGHT 1967 BY MOTOROLA INC. - PRINTED IN U.S.A.

PART NO. 68P43IOTAT9 3-67

Page 2

5. POWER AND REGULATOR
TRANSISTOR REPLACEMENT -
When replacing apower or regulator
transistor, be sure to:

A. Use the transistor specified
in the Replacement Parts List,

B, Coat both sides of transistor
insulator with DC-4 grease
(Motorola Part NO. 11M490487)
to insure proper he at dis sipacion.

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.

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,

Audio Amplifier Plated Board - To
gain access to the bottom side of
this board, remove the two (2)
screws at the front side of the radio
(see photo). To remove the board
for servicing, remove the screw
from the mounting bracket, unsolder
the tabs, straighten the tabs, then
remove the mounting bracket.

7. OUTPUT TRANSFORMER AND
FILTER CHOKE REPLACEMENT -
Remove 4 screws, 2 at front side
and 2 at rear (see photo); also un-
solder control ground leads from
wraparound and pull out wraparound
far enough to remove transformer
or filter choke.

8, 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 that is known
to be good.

9. 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 up and down tape
travel. The head and capstan should
be cleaned whenever the unit is ser-
viced 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.

(CAUTION should be exercisedwhen
cleaning playback head to prevent
getting cleaner on anyplastic parts.)

2

CHASSIS
GROUND
LEAD

P RE-AM P

PLATED BOARD CLIP

PRE-AMP CHASSIS REMOVAL

AUDIO AMP

CHASSIS REMOVAL

UNSOLDER

RETAINING

FILTER CHOKE &

TRANSFORMER REMOVAL

GAINING ACCESS TO PLATED BOARDS, FILTER CHOKE
AND OUTPUT TRANSFORMERS

TAPE HEAD
TAPE CARTRIDGE
SLOT

ERASER END OF PENCIL

CAPSTAN SHAFT

USE COTTON SWAE

MOISTEIED WITH ,
ISOPROPYL (RUBBING) ALCOHOL

DO NOT USE CARBON TETRACHLORZDE

DEPRESS MOTOR SWITCH
WITH ERASER END OF
PENCIL

TAPE HEAD & CAPSTAN CLEANING

10. HEAD DEMAGNETIZLNG - Do
not use magnetized screwdrivers
and wrenches near the head since
these can magnetize the head. The
head may also, after a long period
of time, acquire some residual mag-
netism. A head that is magnetized
will show a definite loss of high
frequency response and an increase
in noise level. Use a commercially
available head demagnetizer, fol-
lowing instructions included with the
unit to demagnetize the head.

11. HEAD REPLACEMENT - The
location of the tape head with respect

to its mounting bracket is very
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 HHead Positioning Adjust-
ment".