Tandberg TR 2055 Service Manual

Page 1

TANDBERG
T? 2055

Service Manual

CONTENTS

Changing and cleaning P/B selectors (switches) ................................ page 2
Mechanical service ...................................................... page 3
FM alignment procedure ................................................. page 4
FM circuit diagrams - Stereo decoder diagram ................................ page 7
RlAA/input, Circuit diagram .............................................. page 9
Ill?» selector, circuit diagram .............................................. page 9
Power-Amplifier, circuit diagram ........................................... page 1 l

Prc-Amp/Filtcr, circuit diagram ............................................ page 12

Page 2

CHANGING OR CLEANING PUSH BUTTON
SWITCHES

Occasionally the push button Switches will need to be
cleaned and lubricated to maintain trouble free action.

A good cleaning agent should be applied sparingly with a
fine brush, We recommend Tandberg Kliiberfett" or
Wahlerfett from our Service Department.

Alcohol or methylated spirit may also be used for

cleaning and vaseline may be used for lubrication
afterwards.

NOTE! Avoid touching the contacts with your finger 7*
it could cause corrosion.

Avoid using cleaning agents that could attack the metal
parts.

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 subsidiary
companies,

Tandberg Contact Spray

NOTE! Slide switches (mode selectors) are available complete as a
replacement part.

If necessary, the switch can be cleaned, and the plungu or the con-
tact unit can be changed. For these operations the switch must be
dismantled

DlSMANTLING THE CONTACT CASE/SLIDE
CONTACTS

I Unsolder the contact case from the solder side.

I Push the plunger about half way in and move it slightly for-
wards and backwards and at the same time grip the contact
case solda tags with flatnose pliers (see figure). The back end
of the plunger must lie edge to edge with the contact case as
shown by >I< in the figure.

I Pull the contact case out.
I Pull the sliding contact out of the case

DISMANTLING THE PLUNGER

Remove all four contact cases as described above.

I Move therinterlocking plate to the left (seen from the front) to
release the plunger, and pull the plum out. See figure.

DISMANTLING THE PLUNGER

I Pull the spring slightly forward so that the locking clip is free
at the edge.

I Use tweezers as shown in the figure

I Press the plunger right in.
lush me locking clip backward and lift it up.
NB! The locking pin lies loose in the locking clip,

I The plunger can be pulled out
NB! The wring contacts on the plunger are loose.
The spring is slightly cortical so that if you remove it from
the plunger, take care to replace it with the smallest end
against front of the plunger.

SWITCH HOUSING

LOCKING CLIP

SPRING TWEEZERS

PLUNGER