Toshiba 2857 DB Manual

TOSHIBA 2857 DB
General Information
Chassis: C5SS
Matrix
Item
Adjustments (Not Service mode) .................................................................. 2152 DB
2. It is essential that to maintain the safety of the
X-RAY RADIATION PRECAUTION
customer all cable forms be replaced exactly
as supplied from factory.
1. The E.H.T. must be checked every time the
3. A small part of the chassis used in this
receiver is serviced to ensure that the C.R.T.
receiver is, when operating, at approximately
does not emit X-ray radiation as result of
half mains potential at all times. It is therefore
excessive E.H.T. voltage. The nominal E.H.T.
essential in the interest of safety that when
for this receiver is 31.5 kV at zero beam
serving or connecting any test equipment the
current (minimum brightness) operating at
receiver should be supplied via a suitable
240V a.c. The maximum E.H.T. voltage
isolating transformer of adequate rating.
permissible in any operating circumstances
4. Replace blown fuses within the receiver with
must not exceed 32.0 kV. When checking the
the fuse specified in the parts list.
E.H.T., use the 'High Voltage Check' proce-
5. When replacing wires or components to
dure, using an accurate E.H.T. voltmeter.
terminals or tags, wind the leads around the
2. The only source of X-RAY radiation in this
terminal before soldering. When replacing
receiver is the C.R.T. To prevent X-ray
safety components identified by the interna-
radiation, the replacement C.R.T. must be
tional hazard symbols on the circuit diagram
identical to the original fitted as specified in
and parts list, it must be a Toshiba approved
the Parts List.
type and must be mounted as the original.
3. Some components used in this receiver have
6. Keep wires away from high temperature
safety related characteristics preventing the
components.
C.R.T. from emitting X-ray radiation. For
continued safety, replacement component
PRODUCT SAFETY NOTICE
should only be made after referring the
Product Safety Notice below.
Many electrical and mechanical components in
this chassis have special safety-related
SAFETY PRECAUTION
characteristics. These characteristics are often
passed unnoticed by a visual inspection and the
1. This receiver has a nominal working E.H.T.
X-ray radiation protection afforded by them
voltage of 28.5 kV. Extreme caution should be
cannot necessarily be obtained by using
exercised when working on the receiver with
replacements rated at higher voltages or
the back removed. Do not attempt to service
wattage, etc. Components which have these
this receiver if you are not conversant with the
special safety characteristics in this manual and
precautions and procedures for working on
its supplements are identified by the interna-
high voltage equipment. When handling or
tional hazard symbols on the schematic diagram
working on the C.R.T., always discharge the
and parts list. Before replacing any of these
anode to the receiver chassis before remov-
components read the parts list in this manual
ing the anode cap The C.R.T., if broken, will
carefully. Substitute replacement components
violently expel glass fragments. Use shatter
which do not have the same safety characteris-
proof goggles and take extreme care while
tics as specified in the parts list may create X-
handling. Do not hold the C.R.T. by the neck
ray radiation.
as this is a very dangerous practice.
Recommended Safety Parts
Item Part No. Description
A401 23426393 Back Cover
PF, 7000pF, ±3%, 1500V
C440 24082482
C441 24082669 PF, 0.33µF, 250V
C442 24082672 PF, 0.43µF, 250V
PF, 6200pF, ±3%, 1800V
C444 24082519
CD, 2200pF, ±10%
C463 24212222
C801 24082374 PE, 0.22µF, AC250V
CD, 4700pF, ±20%, AC250V
C805 24092281
CD, 4700pF, ±20%, AC250V
C806 24092281
R801 24009954 Metal-Glazed Resistor, 2.2M ohm, 1/2W
R808 24019340 PTC Thermistor, 18 ohm, 290V
R810 24007489 Cement, 3 ohm, 20W
R811 24568271 Cement, 270 ohm, 7W
R824 24569689 Cement, 6.8 ohm, 10W
R841 24531120 FR, 12 ohm, 1/2W
R899 24005007 Metal-Glazed Resistor, 8.2M ohm, 1W
L462 ------------- DY, Supplied with V901
L901 23200276 Coil, Degaussing, TSB-2330BR
T401 23224336 Transformer, Horiz. Drive, TLN1083
T461 23236447 Transformer, Flyback, TFB4115AR
T801 23211891 Line Filter, TRF3164
T803 23217301 Transformer, Converter, TPW3336AR
Q404 A6872801 Transistor, 2SD2253(FA)
Q801 23905084 IC, STR-S6709
Q826 A8643106 Photo Coupler, TLP621(GR)
D801 23316795 Diode, D6SB60L,F05
F470 23144873 Fuse, 1.0A
F801 23144898 Fuse, 3.15A
P801 23372012 Power Cord
V901A 23902891 Socket, CRT, 10P
V901 23312645 Picture Tube, A66EAK252X21
Service Mode General
Instructions
1. ENTERING TO SERVICE MODE
1) Press button once on Remote Control.
See Model Book
5
2) Press button again to keep pressing.
3) Keep pressing the button, press MENU
button on TV set.
RCUT S
32H
(Service mode dIsplay)
2. SELECTING THE ADJUSTING ITEMS
Every pressing of CHANNEL
the adjustment items in the following order.
( button for reverse order.)
3. ADJUSTING THE DATA
Pressing of VOLUME or
the value of data in the range from 00 to FF. The
variable range depends on the adjusting item.
4. NORMAL OPERATION ON THE SERVICE
MODE
Press MENU button on TV.
Adjustment mode
RCUT Address
32H Data
5. EXIT FROM SERVICE MODE
Press POWER button on the remote control to
turn off the TV once.
OTHER SERVICE FUNCTION
The following key entry during display of
adjustment menu provides special functions.
1
button changes
button will change
Service mode
TEST SIGNAL SELECTION
S
Press
Every pressing of button changes the test
patterns on screen as described below in
Press
SERVICE MODE.
Signal off NTSC signals (14 patterns)
PAL signals (14 patterns)
About inside signal: The inside signal is output
at video input terminal from QA01, and is not
output with the pin inserted into terminal.
(Single color signal can be output.)
Signals
Red single colour
Green single colour
Blue single colour
Black single colour
White single colour
Picture
Using method
Purity and White uniformity of CRT
Red single colour.
Picture
Using method
Picture position (horizontal, vertical and slant) in
CRT adjustment.
Making approx. 1 Vp-p signal in QA01.
Signals
Black cross-hatch
White cross-hatch
Picture
Using method
Convergence and vertical amplitude adjustment
Making approx. 1 Vp-p signal in QA01.
Signals
Black cross-dot
White cross-dot
Picture
Using method
Convergence adjustment
Making approx. 1Vp-p signal in QA01.
Signals
H signal (Left, right, white)
H signal (Left, right, black)
Picture
Using method
For checking (of purity drift) of white uniformity
of CRT H signal (Left, right, white).
Check in light area.
H signal (Left, right, black).
Stopping G and B output of Q501
Check in dark area.
Green single colour.
The adjustment will be the best, if the time when
Stopping R and B output of Q501
unevenness of color in light area occurs, is a
Blue single colour.
little longer than that in dark area.
Stopping R and G output of Q501
Making approx. 1Vp-p signal in QA01.
Black single colour.
Making black signal of approx. 1Vp-p in QA01
White single colour.
Making white signal of approx. 1Vp-p in QA01
Signals
W/B adjustment
Picture
Using method
White balance adjustment
White .
White balance adjustment/check in light area
Black part.
White balance adjustment/check in dark area.
Making. approx. 1Vp-p signal in QA01.
Signals
Black cross-bar
White cross-bar