Sharp 70GS-66E User manual

1
70GS-66E
MODEL 70GS-66E
SHARP CORPORATION
PAL I SYSTEM COLOUR TELEVISION
SEJB70GS66E00
SERVICE MANUAL
In the interests of user safety (required y safety
regulations in some countries) the set should restored
to its original condition and only parts identical to
those specified should e used.
Issued: Tent 24 Jan 2001
This document has een pu lished to
e used for after sales service only.
DA-100 CHASSIS
PARTS LISTING..............................................28
CONTENTS
ELECTRICAL SPECIFICATION.......................3
IMPORTANT SERVICE NOTES.......................4
ADJUSTMENTS PROCEDURES.....................5
SCHEMATIC DIAGRAM..................................20
PRINTED WIRING BOARDS..........................10
COMPONENT LOCATION TABLES...............14
RTV servis Horvat
Tel: ++385-31-856-842
Tel/fax: ++385-31-856-139
Mob: [phone]
www.rtv-horvat-d .hr

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70GS-66E
Use this page to keep any special servicing information as Technical Report (Bulletin), Technical Information, etc.
If only part num er changes are required, just change part num er directly the part num er in the Parts Listing Section.
If you need more information, please refer to the Technical Report (Bulletin).
SERVICE MANUAL UPDATE LOG SHEET
Part No.
Tec nical Report No.
Tec nical Bulletin No. Cause / Solution Page No. Application
Data /Serial No.

3
70GS-66E
ELECTRICAL SPECIFICATIONS
•Sweep Deflection ............................... Magnetic
•Picture Intermediate frequency
L’......................................................33.9MHz
L, B/G, D/K, I...............................38.9MHz
•Sound Carrier Trap
L’..................................................40.4MHz
L, D/K...........................................32.4MHz
B/G..............................................33.4MHz
I....................................................32.9MHz
•Adjacent Sound Carrier Trap
L’..................................................32.4MHz
L, D/K, B/G..................................40.4MHz
I....................................................40.9MHz
•Adjacent Picture Carrier Trap
L’..........................................................41.9MHz
L, D/K, I........................................30.9MHz
B/G..............................................31.9MHz
•Aerial Input Impedance
VHF/UHF ................. 75 ohm Un alanced
•Tuning Ranges ..... 45.75MHz thru 855.25 MHz
CATV Special Channels
•White Level
Set rightness control to get total picture tu e cathode current of 600 milliammeter under no signal
condition. Maximum necessary correction of each picture tu e cathode current to get 8550 degrees K+1
MPCD screen temperature should not exceed 15% of its original value.
X=0.290 Y=0.300
WARNING
The chassis in this receiver is partially hot. Use an isolation transformer etween the line cord plug
and power receptacle, when servicing this chassis.
To prevent electric shock, do not remove cover. No user-servicea le parts inside. Refer servicing to
qualified service personnel.
Specifications are su ject to change without prior notice.
•Power Input ...................... 220V-240 Volts AC 50Hz
•Power Consumption
Normal Operation ...................................88W
Stand- y Operation ..................................1W
•Audio Power Output Rating (MPO) / Impedance
Internal Left Speaker ...................... 10W, 7Ω
Internal Right Speaker .................... 10W, 7Ω
Internal Centre Speaker .............. 10W, 7Ω
Internal Su woofer .................... 20W, 4.5Ω
•Speakers
Left / Right ...............................12W, 6 x 12cm
Centre .....................................12W, 6 x 12cm
Su woofer .........................20W, 11cm Round
•Convergence
Static (Centre) .. etween any two colours
Dynamic .............. after static equals zero
•Focus ................ High Bi-Potential Electrostatic

4
70GS-66E
IMPORTANT SERVICING NOTES
Only qualified se vice pe sonnel a e allowed to ca y out maintenance and epai of this eceive .
SERVICING OF HIGH VOLTAGE SYSTEM AND CRT
It is impo tant that the static cha ge is emoved f om the high voltage system when ca ying out wo k
on the eceive . This can be achieved by connecting a 10K esisto (with a suitably insulated lead) f om
the CRT cavity connecto to the CRT g ound tag. This must be ca ied out with the AC supply discon-
nected f om the eceive .
Note the following:
• The CRT in this eceive employs Integ al Implosion P otection.
• If the CRT has to be changed it MUST be eplaced with the co ect type fo continued safe
wo king
• DO NOT lift the CRT by its neck.
• When handing the CRT, ensu e that shatte p oof goggles a e wo n.
• Ensu e that the CRT is discha ge befo e handling.
X-RAY
This eceive is designed to keep any x- ay emission to an absolute minimum. Some fault conditions
and se vicing p ocedu es may p oduce potentially haza dous x- ay adiation levels. This is a p oblem
when in close p oximity to the eceive fo long pe iods of time. To educe any isks associated with
this, please obse ve the following p ecautions:
1. When unde taking any se vicing on this chassis, DO NOT inc ease the EHT to mo e than 28 KV,
(at a instantaneous beam cu ent of 1500µΑ).
2. Ensu e that du ing no mal ope ation the EHT does not exceed 25KV±1.5KV (at a beam cu ent of
1000µΑ). This level has been p eset in the facto y. Always check that this level has not been ex-
ceeded afte ca ying out any epai on the eceive .
3. DO NOT eplace the CRT with any othe type than that specified in the pa ts listing as this may
cause excessive x- ay adiation.
BEFORE RETURNING THE RECEIVER TO THE CUSTOMER
In addition to the above checks, the following should also be ca ied out befo e etu ning the eceive
to the custome .
1. Inspect all the leads to ensu e that they a e d essed co ectly and that they a e not obst ucted o
pinched by any othe pa ts.
2. Ensu e that all p otective devices a e in good condition. These will include nonmetallic cont ol
knobs, insulating fish pape s, cabinets backs, compa tment cove s o shields, mechanical insulato s,
etc.

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70GS-66E
ADJUSTMENT PROCEDURES
All adjustments to this chassis, except for focus, are carried out in the service mode.
••
••
• SERVICE MODE
The service mode is provided to ena le the engineer to correctly set up the receiver to the CRT fitted in the set.
Note that these adjustments may vary from one receiver to another.
To enter the service mode, carry out the following procedure.
1. Connect a test pattern to the antenna terminal.
2. Tune the receiver to this signal.
3. Turn the receiver off using the mains switch.
4. Press volume down and channel up uttons on the
front of the receiver at the same time.
5. Keeping these uttons pressed, turn the mains on.
6. When the set starts up it will e in service mode.
7. Release the two uttons.
••
••
• Use the channel up and down uttons to move etween the options.
••
••
• Use the volume control uttons to change the data.
••
••
• To store the data, use the stand- y utton on the remote control.
••
••
• To exit the service mode, turn the receiver off using the mains switch.
When the service mode is entered the following On Screen Display appears
-SERVICE SOFTWARE AND HEXADECIMAL COUNTER DISPLAY:
SW ON XXXX SW OFF XXXX HOURS ON XXXX
The figures displayed in the XXXX locations are hexadecimal representations of the num er of times that particular
function has een executed. For example if the hexadecimal num er displayed after SW ON was 0E4A, this would
correspond to the receiver eing turned on 3658 times.
Adjustment menu:
The following adjustments can e carried out in the service mode.
CH
4
5
• Horizontal Shift
• East West Width
• Pin Phase
• Pin Amp
• Upper corner correction
• Lower corner correction
• Vertical Linearity
• Vertical angle
• Vertical ow
• Vertical Amplitude
• S Correction
• Extreme Corner Correction
• Vertical Shift
• Red Cut Off
• Green Cut Off
• Blue Cut Off
• Alter NVM Page
• Alter NVM Position
• Alter NVM Value
• Teletext Mix Mode Contrast
• Teletext Contrast
• OSD Contrast
• DVCO Adjustment (Only PAL)
• DVCO Adjustment (Only NTSC)
• Luma croma delay
• AGC Adjustment
• AFT Adjustment (BG-I-L)
• AFT Adjustment (L’)
• OPC Value
• Auto Installation On/Off
Geometry Adjustments
All geometry adjustments are ased on an internally generated test pattern as shown
in figure 1. When carrying out any of the a ove geometry adjustments, use the inter-
nally generated test pattern for guidance.
Fig.1