Sony PS-2250 - Strobe Lamp Replacement; Power Transistor Replacement; Tonearm Assembly Removal

2-9. STROBE LAMP REPLACEMENT
1.
2.
3.
4.
Remove the turntable base as described in
Procedure 2-3.
Remove the four screws (@ PS 4 x 8)
securing the strobe unit to the turntable base.
Pull out the unit.
Unhook the retaining spring from the lamp
cover and then apply a drop of cement solvent
to the lamp. Wait a few seconds, and then push
out the defective lamp as shown in Fig. 2-11.
CAUTION
Too much cement solvent may cause
damage to the unit. Only a few drops are
required to dissolve the rubber-base ad-
hesive.
Install a new strobe lamp. Take care that the
glowing side (front) of the lamp is positioned
as shown in Fig. 2-11
Note: Apply a drop of rubber-base adhesive
to the rear side of the lamp when
installing the lamp.
glowing
side
Fig. 2-11. Strobe lamp removal
and installation
2-10. POWER TRANSISTOR REPLACEMENT
1.
2;
3.
Remove the power supply chassis as described
in Procedure 2-6.
Remove the screw (@ P 3 x 10) securing the
power transistor to the heat sink.
Cut the emitter and base leads of the defective
power transistor with a diagonal cutter.
This prevents mica-washer damage when remov-
ing the defective power transistor.
When replacing the power transistor, apply a
coating of heat-transferring grease to both
sides of the insulation mica washer.
Any excess grease squeezed out when the
‘mounting. screw is tightened should be wiped
off. with a clean cloth. This prevents it from
2-11,
2-12.
accumulating conductive dust particles that
might eventually cause a short:
TONEARM ASSEMBLY REMOVAL
Remove the shell head.
: Remove the bottom plate as described in Pro-
cedure 2-2.
Unsolder the leads from. the terminal beneath
the turntable base (See Fig. 2-12).
The lead wires are coded as follows:
White ...........0000. L-CH
BUG ic670 3 enon ans L-CH (ground)
Reds conn eines t edie R-CH
Green ...........00005 R-CH (ground)
Remove the hexagon nut securing the tonearm
base to the wooden case.
This frees the tonearm assembly.
Fig. 2-12. Lead wire connection
TONEARM BASE REMOVAL
Remove the tonearm assembly as described in
Procedure 2-11.
_ Remove the lock lever by turning it counter-
clockwise.