Adjustment; Adjustment Procedure; Standard Adjustment Conditions; Pre-Adjustment Of Power Supply (Pwb-1641) - Tatung OMNISCAN SERIES Service Manual

2. ADJUSTMENT PROCEDURE
2.0 Standard Adjustment Conditions
A. Power supply voltage: AC 110V, 60Hz.
B. Warm up time:
The display must be on for at least 20 minutes
before starting alignments.
This is especially critical in color temperature
and white balance adjustments.
C. Instrument: CHROMA-2000 or similar PATTERN
GENERATOR
D. Setting:
(G+Sync.) Sync. Switch OFF (signal 86/88/89)
(H/V) Sync. Switch ON (signaI81/82/83/84/87)
(H + V) Sync. Switch ON (signal 85)
*
When G + Sync. output, simultaneously output a
H/V to the H. Sync. line, so the Sync. Switch
should set at "OFF". (Refer 2.15)
Signal Level switch 0.7V
Contrast Control Max.
Brightness Control Max.
E. Signals
Video: Analog 0.7 Vp-p, 75 ohm
Analog sync. on green
Video: O.7Vp-p
Sync.: 0.3Vp-p
Sync.: TTL level NEGATIVE/POSITIVE polarity
Separate/Composite (Refer 2.15).
(T erminated resistor 1 Kohm)
Scanning Freq.: H 29KHz - 65KHz
V 45Hz - 1 DO Hz
2.1 Pre-Adjustment of POWER SUPPLY
(PWB-1641)
A. The POWER SELECTOR SW. is connected to Pin
A of PWB-1641, for the different line source
input.
Pin ALA
UL/CSA AC 115V SHORT
HONG KONG/EUROPEAN (TUV) AC 230V OPEN
B. Connect the Dummy Load Resistor with the
proper rating values shown below.
C. Set R818 to minimum position (fully clockwise,
viewed from component side).
Pin
4
3
2
R1
R2
R3
616
258
18.2
ohm/50W (approx.)
ohm/25W (approx.)
ohm/35W (approx.)
D. Adjust R818 (24V ADJ.) so that the voltage on
Pin 2 of P802 is as shown below,
TOSHIBA 17" HITACHI 17"/20" NEC 17"
TUBE TUBE TUBE
Pin 2 24.5V
616
258
T80l
P8l8
D
24V
~DJ.
POWER SUPPLY BOARD
PWB-1641 TOP VIEW
24V
~
P803
0801
r:::::=:J
A
ca05
o
C806 A
o
2.2 Pre-Adjustment of MICRO BOARD
(PWB-1697-2)
+ 12V Adjustment
A. Apply 24V dc voltage to Pin 7 of P5D1.
24V
1l0VlSHOPT
220V20PEN
B. Adjust R556 (12V ADJ.) so that the voltage on
C503 is 12V
(+/-
0.1V).
C. Check the voltage on C514 or R558 is 5.0V (+ /-
0.25V).
=
2-1
=