Connecting/Disconnecting Of Plugs - Philips VR6491 Service Manual

3.4 Capstan rotor unit
The Capstan rotor unit is supplied as a replacement part
in a complete unit with a spring loaded capstan pulley.
Do not remove the retaining ring on the capstan pulley of
the capstan rotor unit or the replacement unit will be
rendered useless (Fig. 4).
For more information see tapedeck manual DM 4/0.
Capstan Rotor
Capstan oe:
Pulley Retaining Ring
Fig. 4
3.5 Variable voltage transformer
Because a hot chassis ground is present in the power
supply circuit, an isolation transformer must be used.
Also, in order to have the ability to increase the input
slowly, when trouble shooting in this type power supply
circuit, a variable transformer is required.
3.6 Prevention of electrostatic discharge (ESD)
All IC's and many other semi-conductors are susceptible
to electrostatic discharges (ESD). Careless handling
during repair can reduce their life drastically.
When repairing, make sure that you are connected with
the same potential as the mass of the set via a wrist
wrap with resistance. Keep components and tools also at
this potential.
3.7 Measurements
All voltages, given on the circuit diagrams, have been
measured in the SP recording mode.
3.8 Parts replacement on Head amplifier ass'y
— Unsnap and remove the shield case.
- Remove the Head Amp CBA by unsoldering the 5
fixing points (A) that connect the shield case with the
Head Amp CBA (Fig. 5).
- Open the side of the shield case slightly and pull out
the Head Amp CBA.
~ After parts replacement it is necessary to resolder the
shield case at points (A) on the Head Amp CBA.
— Re-install the shield case.
VIDEO HEAD AMP CBA
FIXED POINTS (A)
Fig. 5
3.9 Parts replacement on PIP—Module
— Unsolder the shield case 2 points from the lower CBA.
- Remove the plugable module with help of a
screwdriver (Fig. 6).
— Unsolder the 3 fixing points of the shield case of the
PIP—Module (Fig. 7).
— After replacement of parts it is necessary to resolder
the shield case in reverse order.
PMO2— Sh
UNSOLDER SCREWDRIVER
45 169 ANl
Fig. 6
|<+___———- UNSOLDER ——-———>
terme
Fig. 7 45.170 AN
3.10 Connecting/disconnecting of plugs
a. Disconnecting the flexible cable to the trap connector
P1504 and P1508 on the tapedeck (Fig. 8).
— Pull-out both ends of the locking tab which surrounds
the connector to release the connector.
- Remove the flexible cable carefully (See Fig. 8).
- Connecting the flexible cable is done in the reverse
order
Note: Take care not to damage the cable.
b. Flat cable connectors
Connecting/disconnecting is done by carefully pushing
in or pulling out the flexible cable.
Flexible Cable
Operation Panel
Connection C.B.A.
Pull both sides
of tab out together
ge Fig. 8
CS 27 435