Samsung TX20C53X/XET, Service Manual

Page: 23 / 106

Disassembly and Reassembly
Samsung Electronics
4-21
4-5-3 Check Transitional Operation from
RPS to Play
Check transition from RPS mode to play mode :
Using a pre-recorded SP tape, make sure the entry
side of envelope comes to an appropriate steady state
within 3 seconds (as shown in Fig. 4-5-7).
If the envelope waveform does not reach specified
peak-to peak amplitude within 3 seconds, adjust as
follows :
1) Make sure there is no gap between the supply
roller lower flange and the tape.
If there is a gap, adjust the supply guide roller
again.
2) Change operation mode from the RPS to the play
mode (again) and make sure the entry side of
envelope rises within 3 second.
ENTRANCE SIDE ENVELOPE
Fig. 4-5-7 Video Envelope Rising when Operation mode Changes
from RPS to Play Mode
4-5-4 Envelope Check
1) Make recordings on T-120 (E-120) and T-160
(E-180) tape.
Make sure the playback output envelope meets the
specification as shown in Fig. 4-5-8.
2) Play back a self recorded tape (recording made on
the unit using with T-120 (E-120).
The video envelope should meet the specification
as shown in Fig. 4-5-8.
In SP mode, (A) should equal (B).
If the head gap is wide, upper cylinder should be
checked.
A
B
Fig. 4-5-8 Envelope Output and Output Level
4-5-5 Tape Wrinkle Check
1) Run the T-160 (E-180) tape in the playback, FPS,
RPS and Pause modes and observe tape wrinkle at
each guide.
2) If excessive tape wrinkle is observed, perform the
following adjustments in Playback mode :
Tape wrinkle at the guide roller S, T section :
Linearity adjustment.
Tape wrinkle at tape guide flange :
ACE head assembly coarse adjustment.
4-6 Reel Torque
1) The rotation of the capstan motor causes the
Holder Clutch Ass’y to rotate through the Belt
Pulley.
2) The spring wrap PLAY/REV of holder clutch ass’y
drives the disk reel S, T through gear idle by rota-
tion of gear center ass’y.
3) Brake is operated by slider cam at FF/REW mode.
4) Transportation of accurate driving force is done by
gears. (Gear Center Ass’y)
Note : If the spec. does not meet the followings speci-
fications, replace the holder clutch ass’y and then
recheck.
MODE TORQUE g/cm GAUGE
PB 42 ± 11 Cassette Torquemeter
RPS 145 ± 30 Cassette Torquemeter
<Table 2-1>