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F — MAINTENANCE NOTES 

1.

 

Removal of backplate 

Remove two screws from the top of the backplate which may 

then be hinged out from the bottom and lifted away. 

2.

 

Access to the convergence panel 

The convergence panel is located on the front of the receiver in the 

top right-hand corner, behind the upper moulded grille. To remove 

the grille, lever out the name plate by pressing it in at one end (see 

Fig. 2) then withdraw retaining screw A and lift out the grille. 

 

Unhook the assembly containing 

CI701 

and R1702 and 

remove 

the four securing nuts from the 

corners 

cf the shield 

which may 

then be withdrawn. The degaussing coils may be released from 

the 

shield by bending back the retaining tabs. Fit the new coils 

to 

the 

shield and clamp them by bending 

over 

each tab, then solder the 

coil leads to the respective tag strip. 

When 

reassembling the shield, 

ensure that spacers, washers and nuts are assembled in the correct 

order (see Fig. 3). 

 

Fig. 3. Assembly of C.R.T. and shield  

SC 3809 

Fig. 2. Removing convergence cover  

3 .

 

T o   l o w e r   c h a s s i s  

Remove two self-tapping screws from the top of the chassis, then 

swing back the chassis to the extent of the securing lead. 

4 .

 

Removal of the tuner assembly  

Unplug  the  I.F.  lead and  two  fly-leads connecting  the tuner  to the 

receiver.  Loosen  three  screws  securing  the  aerial  panel  to  the 

mounting bracket on the chassis and detach the panel. Release the 

single fixing screw from the tuner mounting bracket after which the 

tuner, complete with leads, may be withdrawn from the cabinet. 

5 .

 

Removal of the control panel 

Pull off three control knobs and release four screws from the rear 

of  the  control  panel.  The  panel  (still  attached  by  its  connecting 

leads) may now be withdrawn from the cabinet. 

6 .

 

Removal of the convergence unit 

Remove four 4BA nuts and shake-proof washers from the corners 

of the convergence control panel. The panel (still attached by its 

leads) may now be withdrawn from the cabinet. 

7 .

 

Replacement of degaussing coils L1723/4 

Remove  the  main  chassis,  tuner  assembly,  control  panel  and  con-

vergence unit together with the convergence yoke, deflection coils 

and blue lateral unit. Lay the cabinet face downwards, supported 

at each corner to prevent the C.R.T. taking the weight of the cabinet. 

8.

 

Removal of the C.R.T. 

WARNING 
Extreme care must be taken when handling the C.R.T. and all safety 
precautions must be taken. 

Carry  out  the  procedure  as  stated  above  for  degaussing  coil  re-

placement. When the metal shield has been withdrawn, the C.R.T. 

may be lifted away from the cabinet. 

Note. 

When the chassis, deflection coils, etc., have been re-assem-

bled,  the  receiver  should  be  allowed  to  warm  up  for  at  least 

20  minutes  before  any  convergence  or  chroma.  adjustments  are 

attempted. The  blue lateral shift assembly should  be  fitted  on  the 

C.R.T.  neck  with  its  shift  magnets  horizontal,  and  the  lead  tags 

pointing  to  the  base  of  the  tube.  The  whole  assembly  must  be 

mounted  as  close  to  the  convergence  yoke  as  possible,  allowi  e  - 

sufficient space for the purity rings to be turned. 

G — L.O.P.T. ASSEMBLY 

Before  replacing  any  valves,  components,  etc.,  in  the  L.O.P.T. 

assembly, the anode cap of the C.R.T. should be disconnected and 

short circuited to chassis to remove any residual charge remaining 

on the tube. 

1.

 

PL509 and PY500 removal 

Unclip the wire cage top cover, pull off the top cap connections 

then remove the valves. 

2.

 

E Y 5 1   r e m o v a l  

Unclip the wire 

cage top cover and remove the lower side plate 

(2 screws at the back of the plate). Unsolder the three leads from 

the valve to the tag panel, then fit a new valve. When replacing the 

side plate, ensure that the focus panel 

lug 

seats correctly in the slot 

in the metal side plate. 

3.

 

P D 5 0 0   r e m o v a l  

Remove  the  main  metal  side  plate  (6  screws).  Loosen  the  four 

screws securing  the top plate together with the valve  base, and 

slide the plate upwards to allow the valve to be withdrawn from 

its holder. 

 

 

121 

 

MOUNTING BRACKET FZR 
DEGAUSSING SHIELD 

12 mm 

122 

123 

119' 

 

CRT.  FIXING 

BRACKET 

117 

- - - -   - -

C A B I N E T  

FRONT 

/

115 

120 

1

,

21. 

SD 3933 

Page Six 

Summary of Contents for G22K511

Page 1: ...VERS c es C O MMB I N E D E L E C T R O NI C S ER V I C ES LI MI TE D 604 PURLEY WAY WADDON CROYDON CR9 4DR TELEPHONES Spare part orders 01 686 3831 General service enquiries 01 688 7722 After business hours Recorded messages on both lines Telex 262308 AUGUST 1969 Please quote CES 739 when ordering further copies CES 739 ...

Page 2: ...d ILLUSTRATIONS Fig No RECEIVER IDENTIFICATION 1 SPRING RESISTOR R1073 If2 CONVERGENCE COVER 3 ASSEMBLY OF C R T AND SHIELD 4 C R T SHIELD 5 TRIM PLAN 6 THIRD HARMONIC TUNING 7 DEFLECTION ASSEMBLY 8 CONVERGENCE PANEL 9 TERMINATING PAD 10 DAMPER DETECTOR UNIT 11 DETECTOR UNIT 12 15 RESPONSE CURVES 16 BIAS NETWORK 17 X Y DISPLAYS 18 BLOCK DIAGRAM 19 CONVERGENCE ASSEMBLY WIRING 20 L O P T ASSEMBLY UP...

Page 3: ...G22K511 G25K512 Page Two ...

Page 4: ...T2144 BC148 T2145 BC148 T2146 BC148 T2147 BC148 T2624 BF197 T2755 BF173 T3401 BF180 T3402 BF182 T3403 BF183 T3495 BC108 T7011 BF195 T7012 BF195 T7013 BF194 T7014 BF194 T7015 BC107 X1101 BY127 X1102 BY127 X1103 BA148 X1104 BA148 X1105 BYX10 X1106 BA148 X1292 BA148 X1293 BA148 X1294 BA148 X2151 0A91 X2152 BA154 X2153 0A91 X2530 AA119 X2531 AA119 X2625 0A90 X2756 0A90 X3496 BZY88 X4140 BA148 X4141 BA...

Page 5: ...l trimming tool A special star shaped trimming tool is necessary for the alignment of the tuner I F coil and also for adjustment of certain other cores This trimming tool is available as part of the Philips trimming tool kit 800 TX and engineers are advised that any attempt to adjust these cores with a non standard tool may damage them 5 Use of the circuit diagram a The complete circuit of the G6 ...

Page 6: ...under the tags and not wrapped around them 2 Ballast resistors During manufacture a high melting point solder is employed on all connections to the supply ballast resistors R1052 R1053 It is most essential that this grade of solder e g Ersin Comsol Alloy is used with a high temperature soldering iron if this component is replaced 3 Thermal fuses FS1108 and FS1110 Two thermal fuses FS1108 and FS111...

Page 7: ...hdrawn from the cabinet 7 Replacement of degaussing coils L1723 4 Remove the main chassis tuner assembly control panel and con vergence unit together with the convergence yoke deflection coils and blue lateral unit Lay the cabinet face downwards supported at each corner to prevent the C R T taking the weight of the cabinet 8 Removal of the C R T WARNING Extreme care must be taken when handling the...

Page 8: ... all the tappings on the line trans former windings are available externally via the two 10 way sockets mounted on the side of the E H T can assembly and connections to many components can be made either on the printed panel or within the valve compartment of the assembly once the gauze screen has been removed In cases of arcing due to breakdown of a component inside the assembly it may be first n...

Page 9: ...2 o 0 0 0 1 0 FOCUS L L L L 2744 2746 2745 2747 PRE SET A G C c i 7 1 0 5 7 L L 72 2 3 4 2 5 2 7 8 3 L 10 0 OD 9 r gd R2092 n L L L2598 0 _____11_2596 7 2555 2554 L2564 0 L2621 L2620 L 2 5 8 6 L2773 L2775 Is F1271b 12 L 2643 4 L264 W611 R2073 A M REJECTION L2603 I 5 5 1 L 2 5 26 L2528 9 LUMINANCE FEED TO C R T CATHODE L2503 l L2504 R7285 I 1 C R T CUT OFF R1167 CONTRAST sl 75Z3 7559 60 7561 L 7 6 ...

Page 10: ... picture is correctly set up Adjust R5045 for optimum focus 10 Vertical hold control R4098 Adjust vertical hold control R4098 to obtain a correctly locked picture 11 Vertical bias control R4105 Before adjusting R4105 check that the boost voltage is correct see para 2 Connect a voltmeter across R4117 pin 7 V4004 to chassis then adjust R4105 to give a reading of 12 5 volts 12 Height control R4101 Be...

Page 11: ... each control Degaussing The receiver is fitted with an automatic degaussing circuit which operates each time the set is switched on from cold However in cases where the C R T and or associated metal parts have been subjected to extra strong magnetic fields it may be necessary to pass an external degaussing coil across the C R T face and in each corner before purity convergence adjustments are car...

Page 12: ...Page Ten ...

Page 13: ...n The solder tags on L1523 are at H T potential 4 Converge the horizontal lines at the bottom of the screen with control 3 and the horizontal lines at the top of the screen with control 4 5 With controls 7 and 8 converge the left and right hand vertical lines 6 Check static convergence and readjust if necessary 7 Switch on the blue gun depress button 17 again 8 Adjust controls 10 11 and 12 to make...

Page 14: ...Page Eleven ...

Page 15: ... warm up period of at least 20 minutes should be allowed for thermal stabi lisation of both receiver and test equipment Leads should be as short as practicable in order to have least effect on the response curve When the sweep generator is connected to the various injection points stated the terminating pad shown in Fig 9 should be used The adjustment of certain vision I F coils will affect both l...

Page 16: ...om X7326 and pins 4 and 5 of V7008 then check the adjustment of R7179 and R7206 see section H paras 22 and 23 Note When alignment of the chroma bandpass circuit has been completed the decoder alignment must be checked particularly the setting of L7559 60 and L7561 I F ALIGNMENT TABLE Inputfrom C20 4I sweep generator to and turn R2092 fully clockwise TP7 tuner injection point via the terminating pa...

Page 17: ... normal picture Connect a high impedance voltmeter from pin 2 of V7003 to chassis ve lead to chassis Adjust L7624 6 for maximum negative reading on the meter approx 4v OVERALL CHROMINANCE BANDPASS RESPONSE 503904e Fig 13 37MHz 33 5MHz RESPONSE AT COLLECTOR T2143 503904f Fig 15 4 R7618 discriminator balance Apply a colour signal to the aerial socket and set up the controls for a normal picture Conn...

Page 18: ...ips of the duplicated ellipses o 17B shows these ellipses before the adjustment is carried out 7 Adjust L7562 3 so that the diagonal ellipses especially on the magenta green axis become as thin as possible It may not be possible to make all the ellipses into thin lines with L7562 3 in which case the best compromise should be achieved 8 Synchronise the reference oscillator by removing the 1 0v sour...

Page 19: ...Page Fifteen ...

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