Motorola u 5 mmt service manual

Page 1

MOTOROLA

GENERAL INFORMATION
TYPE

Automotive type all-transistor
superheterodyne AM radio for
standard broadcast reception; op-
erates from 12 volt negative or pos-
itive ground system (by changing {a
polarity reversing plug onthe radio).

Model U5MMT is designed for in-
stallation in Mack trucks; Model
U5MW is designed for installation
in White Motor Co. trucks.

These receivers contain a plated
chassis board, 6 transistors and Z
diodes.

WARRANTY SERVICE
STATION PROCEDURE

1, A defective in-guarantee radio
must be accompanied by the Custom»
er's Guarantee Policy Tag. This

Guarantee Labor Claim is to be re-
tained by the authorized service
station for his files,

truck radio

MOTOROLA

U5MMT

U5MW

k7 M service manual

MANUAI. 68P43IOIA16

MACK TRUCKS INC.

204SX28

WHITE MOTOR CO.

891600

M ODEL U5MMT

MODEL U5MW

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

REHOVE ANDJNSERT POLARITY REVERSING
PLUG TO CORRESPOND WITH BATTERY GROUND.

eliminator is used as a power source
in place of a battery, it must be well
filtered and regulated.

Z. PLATED CHASSIS BOARD DE-
SCRIPTION - Motorola's PLAcir
chassis has plating on both sides of
the chassis board, The exposed side
contains the actual circuit connec-
tions while the plating on the com-

g 0' tag must be properly filled in by no-charge $33115 '5: the thusfiomdar. If ponent side of thechassis board
- U the Mack or White Motor Truck you are no a rea Y au 9 3.5 a prov1des a convement 1135515 B"
a 8 dealer at the time of radio purchase. Motorola Auto Rad) Service Station return for components and circuit
U I- Accept as guarantee repairs only and you are interested in handling wiring. Plating 0 the component
a a 0 those radios within the guarantee 115 SSYVKC? please contact your side also provides shielding between
:- N E 0 period, The removal or re-install- Motorola Distributor 501 complete the top and bottomofthe unit similar
5 § E 8 ation of this receiver is customarily detafls' 50 a metal ShFSSiS WhiCh incorpor-
gg i3 performed by the Mack or White ates hand mung.
V I Motors Truck dealer and is not
covered by this guarantee. Also, SERVICE NOTES 311 B1; theolgrlliftionsh at? carneld
4 the removal of motor noise tire . roug e on C 35515 in mu '
.a l . . ' 1. Make certain the "A leadis con- tiple paths to the B- side, This in-
O I- stat1c, electrical interference, nected ro erl to ower s C
M E 3 fault installations and aerial re- . p p Y P 'our e, sures a good low resistance return
0 E E pairsyare not considered as guaran» Len Ched position 9f PDIENW re- path, Two separate andindependent
8 g :2 tee re airs and therefore ex enses versing Phlg otherwise damage to paths are F""""ii"31 50 ground.
2 P s , P . receiver may result. If a battery
related to such servxces should be
' handled by the car dealer. 3 TO SERVICE PLATED CHASSIS
, ~c .
'3. POLARITY REVERSING SOCKET BOARD _ To remove the plated
§ 2. Fill in MotorolaGuarantee Labor i- o chassis from the radio housing,first
2 Claim, Part Number 68P60016A30, set the dial ointer to low end (540
P05 non NOTCH P
: and mail Green and Pink copies to: I Y FOR 0 Kc), then remove the dial scale and
3 9355*: 0 0 background. Release the two chassis
1 Motorola Guarantee Service locki s rin cli s and carefull
= GROUND , o g P g P Y
2 Motorola Automotive Products, Inc. 4"! 9 lift chassis board out ofhousing (the
g 9401 West Grand Avenue f \ lead lengths are long enough to per-
4 ~ 3 POSITION norca nus - -
Franklin Park, Illinois. \h out this - see photo on next page).
WAY FOR "E6ATAVE The chassis can now be serviced
Q 3. The yellow copy of the Motorola NOTE: GROUND from top or bottom.

After servicing is performed, re-
install plated chassis board. Make

MOTOROLA INC.
PART NO. 68P43101A16 3.67

9401 WEST GRAND AVENUE, FRANKLIN PARK, ILLINOIS
PRICE 20 CENTS COPYRIGHT 1967 BY MOTOROLA INC. - PRINTED IN U.S.A.

Page 2

certain rear ofboardis seatedprop- A. Use the transistor specified is basically similar to servicing

erly in channel of insulator; then in the Replacement Parts List. tube sets, First, isolate the defec-
lock chassis in place inits mounting tive stage through signal injection;
spring clips. B. Coat both sides of transistor next, through the use of voltage and
insulator with DC-4 grease resistance measurements, plus
4, TRANSISTOR REPLACEMENT - (Motorola Part No. llM490487) Motorolas servicing tools, deter-
? When replacing a transistor (other to insure proper heat dissipation. mine the necessarymaintenance re-
than a power transistor), grasp the quired, Motorola's servicing
transistor leads between transistor C. Securely and evenly tighten methods and aids, when properly
body and plated chassis board with the transistor mounting screws. used, can help make transistor ser-
a pair of long nose pliers to prevent vice easier.
excessive heating of transistor body R f t "P ftabl Transistor
' ' ' e er 0 10 1 e
during soldering operation. TRANSISTOR RECEIVER Radio Servicing" manual (Motorola
Part No. 68P60011A53) and "A Dis-
5. POWER TRANSISTOR RE- SERVICE METHODS cussion Of Transistorized Car
PLACEMENT - When removing a Radios manual (Motorola Part No.
power transistor, be sure to: Troubleshooting transistor radios 68P64980A51).
Q3 06 02 01 Q4 Q5

ANT TRIM

ANT RECEPT

E5

Q 6
2N176
PWR AMP

POLARITY
REVERS I NG
PLUG

2 PARTS lOCATION