Electrical Adjustments - Sony Glasstron PLM-A35 Service Manual

Precautions on adjustment:
1. Perform the adjustment in the given order.
2. Power supply voltage: DC 9 V
3. Equipment required
Electrical adjustment requires the following measuring equip-
ment.
(1) Oscilloscope: 2 phenomena, band 30 MHz or more, with de-
lay mode (use 10 : 1 probe unless otherwise specified)
(2) Pattern generator
(3) Regulated power supply
(4) Digital voltmeter
(5) Frequency counter
(6) Connector for adjustment
4. Measurement points for adjustment are located at CN803 on
the RG-A01 board. The pin No. and signal name of CN803 is
listed below.
• RG-A01 Board, CN803
Pin No. Signal Name
1 GND
2 G OUT
3 B OUT
4 R OUT
5 GND
Preparation:
Connect electrical blocks as shown below.
pattern
generator
S VIDEO IN jack (J401)
or A/V IN jack (J402)
YM-A01 board
DC 9V
Regulated
power supply
DC IN 9 V jack (J101)
DD-A02 board
Note: In the adjustment where the S VIDEO input is designated, if ad-
justment was made with the VIDEO input. The specification of
this set will not be satisfied. Always follow the designation.
If adjustment was made using the VTR with S VIDEO OUT termi-
nal as a signal source, the performance of this set depends on that
VTR. Therefore, use the pattern generator with the Y/C separate
output terminals, if possible.
SECTION 3

ELECTRICAL ADJUSTMENTS

Pin No. Signal Name
6 HD
7 B-Y
8 NC
9 R-Y
10 Y
Connector for check (CN305)
YM-A01 board
Adjusting
Remote
Commander
Set
Extension cable
(J-6082-291-A)
5. Setting up Input Signals
(1) S VIDEO Signal
Connect an oscilloscope to the Y signal pin of the S VIDEO
IN connector, and check that the sync signal of Y signal is
286 mV, video amplitude is 714 mV, and the setup level is 0
mV. (If using the VTR with S VIDEO OUT terminal, check
further that the chroma signal and burst signal do not remain.)
Also, connect an oscilloscope to the chroma signal pin of the
S VIDEO IN connector, and check that the burst signal am-
plitude of chroma signal is 286 mV and it is flat, and more-
over, the amplitude ratio of burst signal to chroma signal is
0.30 : 0.705.
Setup level: Potential difference between black and pedestal
Y signal
White (75%)
535 ± 3 mV
Pedestal
Chroma signal
Chroma
amplitude
Burst amplitude : chroma amplitude = 0.30 : 0.705
Fig. 3-1. Pattern generator's color bar signals
(2) VIDEO Signal
In adjusting this set, video signals obtained from the pattern
generator are used, and therefore these video output signals
must satisfy the specification. Connect the oscilloscope to
the VIDEO IN terminal, and confirm that the sync signal
amplitude of video signals is approximately 286 mV, the
amplitude of video part is approximately 714 mV, burst sig-
nal amplitude is approximately 286 mV and flat, and the level
ratio of burst signal to "red" signal is 0.30 : 0.705.
White (75%)
±
535 3 mV
±
286 3 mV
Pedestal
Horizontal sync signal
Fig. 3-2. Pattern generator's color bar signals
3-1
White (100%)
714 ± 3 mV
Black
±
286
Horizontal
sync signal
±
286
Burst signal
(to be flat)
White (100%)
±
714 3 mV
286
Black
Red
± Burst signal
672 3 mV
(to be flat)
3 mV
10 mV
±
3 mV