Philips PM 5715 - Page 49

8.
Replacing parts
COVER
PIATES
The
top and bottom covers are
secured to
the
rear
panel with
2
screws each.
Remove
the
screws
and pull up the cover.
KNOBS
AND
PUSH-BUTTONS
KNOBS
1 . Pull
out
cap
of
knob
2.
Loosen
nut and pull off knob
3.
When fitting
the knob, ensure
that the white
indications
are positioned as before
removal
PUSH-BUTTONS
1.
Pull
out the button
using
a pair of pliers
HANDLE
1.
Remowe
the two screws
securing
the handle
caps
to the side strips
2.
Remove
handle caps
and pull
out handle
TEXT PLATE
ASSEMBLY
1
. Remove
top and bottom
covers
2.
Remove
all knobs
3.
Snap off
text plate
together with
ornamental
frame
PRINTED-CIRCUIT
CARDS
UNIT
PM
5715-1
1.
Loosen
unit
PM
5715-2
(refer
to paragraph
"UNIT PM
5715-2"
steps 1
and
3)
2.
Remove
all
fast-on connections
3.
Loosen
flexible
card
PM
5715-4
from
connector
4.
Remove
knobs and text plate
assembly
5.
Remove nuts
securing rotary
switches
to
front
panel
6.
Remove screws
securing side
profiles
to
front
panel
7. Pull
up front
panel and take out circuit
card
Note:
The
spare board
should be provided with
push-button
switch
SK9, and resistor
R503 as
shown in circuit board
drawing Fig.
12—3.
UNIT
PM
5715-2
1.
Remove 2
screws
securing card
to
rear panel
2.
Remove
1
screw
securing card
to
front panel
3.
Loosen card from
connector
on
unit
PM
5715-1
4.
Pull
up
and take out the card
UNIT PM
5715-3
1
. Remove
handle and its bearing bushes
2.
Remove
both ornamental strips covering
the
side profile
3.
Loosen 2 screws
securing unit
PM
5715-2
to
rear
panel
4.
Remove fast-on connections
between units
PM
5715-3
and
PM
5715-2
5.
Remove screws securing rear
panel to side
profiles
6. Pull
rear
panel backwards
7.
Remove
the screws fixing the three power
transistors TS302...TS304
to rear panel
8.
Remove
4
screws securing card to rear panel
and
take out card
OUTPUT TRANSISTORS
TS216
-TS217,
TS218-TS219
ON
UNIT PM
5715-2
Note:
These transistors are
placed in lead spring
sockets.
No soldering
is requiredI
1.
Remove circuit
card
PM
5715-2
(refer
to
"PRINTED
CIRCUIT CARDS,
Unit
PM
5715-2")
2.
Loosen screw
and remove leaf spring
3. Pull
up transistors
using a pair of
pliers
IC's
101,
102,
103 ON UNIT
PM
5715-1
1.
Remove
the
top portion of
the 1C
housing
using
a cutter
2.
Remove
the bottom portion
until
the leads
of
the 1C
remains
3.
Unsolder
the leads
one by one
FRONT PANEL
POTENTIOMETERS
R1...R7
1
. Remove text
plate assembly (refer
to
"TEXT
PLATE
ASSEMBLY")
2.
Remove
nuts securing potentiometers
to
front
panel
3.
Disconnect
the
flexible
card
PM
5715-4
and
take out the
assembly
4.
Unsolder
potentiometer
to be replaced.
Avoid excessive
heating.