Tandberg TR 2025 Service Manual

Page 1

TANDBERG
T? 2025

Service Manual

CONTENTS

Page
Changing and cleaning P/B selectors (switches) .......................................... 2
Mechanical dismantling ............................................................ 3
FM-alignment procedure ........................................................... 4
Decoder-alignment procedure ....................................................... 4
FMetuner, seen from the component side .............................................. 5

FM-IF and decoder with IC (U801) [CA 4500 to scrialNo.1853021, seen from the component side. 5
FM-IF and decoder with IC (U801) MC 1310? from serial N01 1853022,

seen from the component side ....................................................... 5
FM circuit diagrams - Stereo decoder diagrams with IC (U801) TCA 4500 to serial No. 1853021 . . a 7
FM circuit diagrams - Stereo decoder diagrams with IC (U801) MC 1310P

from serial No.1853022 ........................................................... 7
RIAA/input, Pre-Amp. and Power Amp, circuit diagrams ................................ 11
Hook a up guide and plugs ......................................................... 12

Page 2

CLEANING THE SWITCHES

Occasionaly the push button switches will need to be
cleaned and lubricated to maintain trouble free action.
Applyagood cleaning agent sparingly with a fine brush.
We recommend 'l'andberg Kluberfctt" or Wahlerfett
obtainable from our Service Department.

Alcohol or methylated spirit may also be used [or
cleaning and vaseline may be used for lubrication
afterwards.

Avoid using cleaning agents that could attack the metal
parts.

NOTE! Avoid touching the contacts with your fingers,
it could cause corrosion.

NOTE! We have developed our own cleaning/lubricating
agent Tandberg Contact Spray in aerosols, and we
recommend it for all types of contacts. These aerosols
can be supplied from our district offices and subsi-
diary companies

DlSMANTLlNG THE SWITCHES

Independent type

FRONT LOCKING BACK LOCKING PLArE

PLATE

SWITCH
HOUSING

PLUNGER Ill SCREW DRIVER

Plunger:
.Set the plunger (1 and 2) to the forward (out) position.
OPull plunger (1) off with the aid of a screwdriver.

.Press plunger (2) right in, at the same time pull plunger
(1) forward and down into the slot in the board,

.Press plunger (2) slightly in (from the inner position),
and at the same time press the front locking plate out
to the left.

NOTE! When re-assembling, the tabs on the locking
plate must point down.

.Lift the back locking plate upi
.Pull the plunger out.

NOTE! The spring for the return of plunger (2) is
located on the back end of the plunger and is loose

Interlocking type

LOCKING
PLATE
TABS SWITCH
HOUSING
TABS

PLUNGER

Plunger:
.Set the plunger to the forward (out) position.
.Pull the locking plate up.
.Pull the plunger out,
NOTE! The spring for the return of the plunger is
located on the back end of the plunger and is loose.
Switch housing:

.When the switch housing is dismantled, it pays to first
unsolder the pre-set pot. located under that particular
switch housing, The pre-set pot. is soldered at two
points on the back edge on the component side.

.Push the preset pot, aside to gain access to the solder
contacts on the switch housing.

.Unsolder the switch housing.

.Straighten up the four tabs which hold the switch
housing.
.Lift up the switch housing.
Independent

W LOCKING CLIP

)4

LOCKING PIN

SPIRAL
SPRING

TWE EZERS
PLUNGER

Plunger:

.Pull the spiral spring slightly forwards so that the
locking clip is free at its front edge.
Use tweezers as shown in the figure.

.Press the plunger right in and hold it there while you
push the locking clip back and lift it up.
NOTE! Take care of the loose locking pin.

.Pull out the plunger.

NOTE! The Contact springs are loose. The spiral springs
are slightly conical, so if the are taken off the plunger
you must take care that the narrowest and is towards
the front of the plunger when it is rc-asscmbled.