Sanyo HT28745 Service Manual page 14

ANTENNA CONNECTIONS
This receiver is designed for UHF/VHF and Digital RF recep-
tion. A 75 ohm terminal is provided for UHF/VHF reception
and a separate 75 ohm terminal is provided for Digital RF
reception. When connecting a CATV antenna system, con-
nect the 75 ohm coaxial cable directly to the 75 ohm
terminal. For 300 ohm VHF antenna, use an adapter (not
included with the TV set).
CIRCUIT PROTECTION
Fuse F601 (4A) is included in the AC line. This fuse must be
replaced with the proper fuse (see Parts List).
CAUTION
FOR CONTINUED PROTECTION AGAINST A RISK OF FIRE,
REPLACE ONLY WITH THE SAME TYPE
4A, 125V FUSE.
ATTENTION : POUR MAINTENIR LA PRO-
TECTION
4A 125V
D' INCENDIE UTILISER UN FUSIBLE DE
RECHANGE DE MEME TYPE 4A, 125V.
+B VOLTAGE CHECK
1. Connect Voltmeter + lead to TJ1 (134.5 V) and – lead to
ground (Power/Deflection board).
2. Connect receiver to AC 120V line.
3. Tune receiver to an active channel.
4. Set the picture controls to the Sports level or Reset (use
MENU key and L or M key or RESET key).
5. Voltage must measure between 133.0 V and 136.0V.
If the voltage is out of range, the power circuit must be
checked. No +B adjustment is provided on this chassis.
HORIZONTAL CENTERING ADJUSTMENT
1. Tune receiver to an active channel.
2. Check that picture is in the horizontal center of TV
screen. If picture is not centered horizontally, perform
steps 3 - 6.
3. Turn off the receiver and disconnect the AC power cord.
(120V AC line)
4. While pressing the VOLUME – key, reconnect the AC
power cord. The Service Menu display will now appear.
5. Select NO. 11E (HPO2: Horizontal Position, Bit 7 - 2) with
L or M key.
6. Adjust the data with numeric keys for horizontal center. To
turn off the Service Menu display, press the MENU key.
HORIZONTAL WIDTH ADJUSTMENT
1. Tune receiver to an active channel.
2. Check the picture for proper width. If width is not cor-
rect, perform steps 3 - 6.
3. Turn off the receiver and disconnect the AC power cord.
4. While pressing the VOLUME – key, reconnect the AC
power cord. The Service Menu display will now appear.
5. Select NO. 119 (HSI2: Horizontal Size, Bit 7 - 2) with
L or M key.
6. Adjust the data with numeric keys for proper width. To
turn off the Service Menu display, press the MENU key.
SERVICE ADJUSTMENTS (Continued)
CONTRE LES RISQUES
VERTICAL SIZE ADJUSTMENT
1. Tune receiver to an active analog channel.
2. Check the vertical size of the picture. If the vertical size
is too large or small, perform steps 3 ~ 6.
3. Turn off the receiver and disconnect the AC power cord.
4. While pressing the VOLUME – key, reconnect the AC
power cord. The Service Menu display will now appear.
5. Select NO. 116 (VS: Vertical Size, Bit 7 - 2) with L or M
key.
6. Adjust the data with + or – key for full scan. To turn off
the Service Menu display, press the MENU key.
VERTICAL CENTERING ADJUSTMENT
1. Tune receiver to an active analog channel.
2. Check that picture is in the vertical center of TV screen.
If picture is not centered vertically, perform steps 3 - 6.
3. Turn off the receiver and disconnect the AC power cord.
4. While pressing the VOLUME – key, reconnect the AC
power cord. The Service Menu display will now appear.
5. Select NO. 117 (VPS: Vertical Position) with L or M key.
6. Adjust the data with numeric key for vertical center. To
turn off the Service Menu display, press the MENU key.
GRAYSCALE ADJUSTMENT
1. Connect a color-bar generator to the analog antenna
terminal.
2. Switch the generator to the white pattern.
3. Set the picture controls to the Sports level or Reset (use
MENU key and L or M key or RESET key).
4. Turn off the receiver and disconnect the AC power cord
(120V AC line).
5. While pressing the VOLUME – key, reconnect the AC
power cord. The Service Menu display will now appear.
6. Select the following service menu items with the L or M
keys and set the data with the numeric keys.
7. Select NO. 106 RD2 (Red Drive) and set data to 7C, NO. 107
GD2 (Green Drive) and set data to 7F, and NO. 108 BD2
(Blue Drive) and set data to 7C.
8. Set NO. 10A RCT2 (Red Cutoff) data to 84, NO. 10B GCT2
(Green Cutoff) data to 4D, and NO. 10C BCT2 (Blue Cutoff)
data to 8D.
9. Set NO. 109 SBR2 (Sub Brightness) data to 32 and
NO. 105 SSH2 (Sub Sharpness) data to 61.
Screen Adjustment
10. Connect oscilloscope probe (at least 50:1) to TP47G and
ground lead to TE47 on the CRT socket PWB.
11. Select "Screen Adjustment" Menu (between NO. 08F
and 0B0) with L or M key (Black Picture).
12. Adjust Screen Control (T402) to obtain 15 Vp-p from
black to white level. (See Figure 2.)
— 14 —
1V
15 Vp-p
Figure 2.