High Voltage Adjustment; Final Assembly Adjustment (Adjustment Should Be According To Below Order); Cut Off Adjustment; Dcu Phase Data Setting - Hitachi 51SWX20B Service Manual

Important: High Voltage adjustment should
!
NOT be adjusted in field. This is
adjusted at factory using precise
loads
readjusted.
1.4 High Voltage Adjustment (should NOT be
readjusted in field).
Adjustment preparation
(1) Connect High Voltage meter to FBT High Voltage
output. Connect GND of High Voltage meter to CPT
GND or FBT GND.
(2) Check that High Voltage adjustment VR (RH17) is
set to mechanical center. (located behind FBT on
DEFLECTION PWB).
(3) Receive circle pattern signal.
(4) VIDEO control should be reset.
Adjustment procedure
(1) Adjust High Voltage to following spec. by turning VR
RH17 slowly. ADJ. SPEC = 30.2KV±0.3kV.
(2) After adjustment, fix VR RH17 with Silicone glue
(KE40RTV).
High Voltage Adjustment VR.
RH17
2. FINAL ASSEMBLY ADJUSTMENT

2.1 Cut Off Adjustment

Adjustment Preparation:
Adjustment preparation
1. Allow 20 minutes pre-heat run.
(1) Adjust screen VR's on Focus Pack fully
2. Set video conditions to factory presets. counterclockwise.
(2) Adjust Focus VR's on Focus Pack fully
clockwise.
Adjustment Procedure:
(3) Set video conditions to factory preset.
1. Access the I2C Adjustment Mode
(4) The vertical incident illumination on the screen
1.1 On the front panel, press and hold the INPUT
should be 20 lux or less (room should be dark).
button, then press the POWER button; release both
after hearing HV startup.
2. Select SERVICE from adjustment menu by
pressing the button on the remote. This will
collapse the vertical deflection.
3. Turn all screen (G2) controls to the full counter-
clockwise position.
and should NOT
CONV.
HEATSINK
DEFLECTION PWB.
4. Bring up each screen G2 control, one at a time,
Adjustment procedure
until that color is just barely visible. (Also, adjust
(1) Press and hold INPUT key on control panel and
the focus control for each color to obtain optimum then POWER ON to access I
mode.
be focus.)
(2) Choose "SERVICE" item from I
5. After all colors are finished, press the
menu by pressing THUMB STICK
on the remote to un-collapse the vertical, and
(3) Screen VR should be turned clockwise gradually
return to normal.
and set so that retrace line begins to appear.
(4) Return to "NORMAL" mode by THUMB STICK
NOTE: Never power off the TV while in the Service
again.
position of the I2C Adjustment Mode (vertical
(5) Adjust Focus VR's so that focus is even all
collapsed) as CRT damage may result.
around screen.

2.2 DCU Phase Data Setting

Adjustment preparation
(1) Cut off adjustment should be finished.
(2) Set video conditions to factory preset.
Adjustment procedure
(1) Receive any NTSC signal.
(2) Push "SERVICE ONLY" SW on DEF./CONV.
PWB. (Enter to DCU ADJ. mode).
(3) Push A/V NET key on R/C. (Green cross hatch is
displayed).
Then push EXIT key on R/C. (Character pattern
is displayed. This is the PHASE setting mode).
(4) Set PH-H phase data as shown below by using
4 and 6 key on R/C.
(5) Set PH-V phase data as shown below by using
2 and 5 key on R/C.
(6) Set CR-H phase data as shown below by using
THUMB STICK
(7) Set CR-V phase data as shown below by using
THUMB STICK
(8) Push A/V NET key on R/C to exit from the
PHASE mode.
(9) Push PIP MODE key 2 times on R/C to write the
phase data to memory.
(10) When Green dots are displayed, push MUTE
key to return to DCU ADJ. mode.
(11)Push "SERVICE ONLY" SW to return to RF or
VIDEO mode.
36
DP27/27D
C adjustment
2
C adjustment
2
.
and key on R/C.
and key on R/C.
PHASE MODE
PH-H :CD
PH-V: 04
CR-H: 35
CR-V: 0A
button
CH 8