Page 1: ...585 123 01 SERVICE MANUAL Monochrome Video Monitors ZVM 1240 1240 E 1240 EM 7 H Idata systems 860 111...
Page 2: ...vice Bulletins SERVICE DATE BULLETIN OF CHANGED NUMBER ISSUE PAGE S PURPOSE OF SERVICE BULLETIN LIMITED RIGHTS LEGEND Contractor is Zenith Data Systems Corporation of St Joseph Michigan 49085 The enti...
Page 3: ...M 1240 14 10 B Supply Schematic ZVM 1240 E 14 Servicing 8 11 CRT Board Component Location 15 Safety and Service Guidelines 8 12 CRT Board Waveforms 15 AC Leakage Test 8 13 CRT Board Schematic 15 Other...
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Page 5: ...uired when operating the ZVM 1240 with a Zenith PC Series computer LED POWER INDICATOR POWER CORD HORIZONTAL HOLD SIGNAL CABLE FRONT Figure 1 ZVM 1240 and ZVM 1240 E Monitors Characteristics Refer to...
Page 6: ...4 VAC 50Hz 0 2A ZVM 1240 E 35 Watts both models 12 inch 30 cm diagonal Amber H S micromesh anti glare filter 12 7 kV anode voltage Video TTL level Highlight TTL level Horizontal sync TTL level positiv...
Page 7: ...and pressing the RETURN key The screen will be filled with the letter Z or any other character inserted in line 20 c To end the program press the CTRL and BREAK keys at the same time Installation Lis...
Page 8: ...ESS 500VDC IV O 60 VDC VIDEO INPUT 00 1 1 BRIGHTNESS ___ FOCUS 16 2VDC HIGHLIGHT INPUT VERTICAL SYNC 0o DI HORIZONTAL f 8 0 1 1 SYNC V HORIZONTAL HOLD Q CABLE SHIELD Page 4 CONTROL 120VAC 60Hz ZVM 124...
Page 9: ...RX506 and filtered by CX511 to provide a 24 VDC input to the emitter of OX502 This transistor along with OX503 OX504 and as sociated circuitry form the power supply regulator RX503 is the B adjustment...
Page 10: ...m is determined by the bias voltage on pin 8 This voltage is determined by a series of clip resistors R106 R107 R109 R127 and R132 that match the integrated circuit to the monitor Page 6 Horizontal Ou...
Page 11: ...ns from the hot filament and preventing them from striking the CRT Diode CR108 is reverse biased preventing CX124 from discharging through it Circuit Description Brightness Adjustment of master bright...
Page 12: ...d the original de sign be modified or altered without permission of Zenith Electronics Corporation Page 8 A C VOLTMETER 5K OHM VOLT MINIMUM I I 22 4384 15uF AC TVPE II rh II PLACE THI ROUND 63 10401 7...
Page 13: ...Soldering iron 25 to 40 watt Solder 60 40 HE 331 13 Desoldering braid HE 490 185 Cable ties HE 354 59 Lint free cloths Servicing TEST EQUIPMENT Oscilloscope DC to 35 MHz triggered sweep with low capac...
Page 14: ...ve CRT defective Focus control defective CRT socket board defec tive Main circuit board defec tive Horizontal hold control de fective Horizontal processor IC101 defective Table 1 contInued General Tro...
Page 15: ...0202 0204 l201 open 2 Signal cable defective Servicing Adjustments Use a computer to provide signals for the following adjustments B 16 2 V VOLTAGE NOTE This adjustment may interact with the focus adj...
Page 16: ...ded reduce the size of the ferrite magnets by cutting off a small portion with diagonal cutters Page 12 Cleaning Procedures WARNING Be sure that the monitor s power cable is unplugged before you clean...
Page 17: ...E 0103 J l Io I I f 1i r ti 2 t 1 g 1 1 i I J JIi l_________________J I l I I MAIN BOAi EJ CRT BOARD 1 1 C406 To022 I I I 09 T l I _ 1 Q203 I Z02 1 61 L201 8 ____ c T B t J_c BOARD 1 RI O 2201 U3 lit...
Page 18: ...__ J Figure 9 B Supply Schematic ZVM 1240 Page 14 I I I TRANSISTOR LOCATION QXso 1 QXS02 QXS03 QXS04 B 2 00 22 4S 616 2 41 E 0 00 23 07 20 20 2 90 C 1S7 6 16 20 00 02 0 616 B 16 2VDC B WITH FULL CONTR...
Page 19: ...SOCtKTET i JRO Figure 11 CRT Board Component Location 0203 BASE 0201 BASE Figure 12 CRT Board Waveforms O2 Page 15 9 I C 3OI O4 cr 0 AC COUPLED 0204 COLLECTOR 15 53VDC SEE FIGURES 9 AND 10 FOR Bt 16 2...
Page 20: ...AREFULL Y SLIDE A GROUNDED FLAT SCREWDRIVER TIP UNDER THE LIP OF THE ANODE LEAD Figure 14 ZVM 1240 1240 E Exploded View WARNING DISCHARGE HIGH VOLTAGE BEFORE ATTEMPTING LEAD REMOVAL Page 16 MAGNET I Y...
Page 21: ...ord before attempting to reposition the monitor 1 2 Switch off the monitor power and disconnect the power cable from facility power Disconnect the video cable connector from the computer Disassembly R...
Page 22: ...OFF switch out of the rear control panel Alternately pry from side to side until the switch is loose Refer to the inset drawing in Figure 14 Page 18 CRT 10 1 Remove the rear cover 130 2 3 4 5 Remove t...
Page 23: ...9 CRT 12 inch amber N A A 13874 Anti glare filter for 100 00761 29 11 114 01150 03 Screw 8 18 x 1 00 hex head 12 19 01080 03 CRT retaining clamp Parts Lists Table 4 continued Major Assemblies Refer to...
Page 24: ...07860 07 33 jl F 25 V electrolytic Electronic Components C302 22 7563 28 22 jl F polyester Refer to Figures 4 7 and 11 C303 22 08004 02 1 jl F polyester CX304 22 07860 12 470 jl F 25 V electrolytic R...
Page 25: ...eral Low voltage general Low voltage general Low voltage general Low voltage general Zener diode 18 V 0 5 watt Low voltage general Low voltage general ZVM 124O Low voltage general ZVM 124O E Low volta...
Page 26: ...09 Screw for QX502 194 00531 Insulating strip for QX502 R137 63 10235 96 10kO 1 4 watt 5 R138 63 10244 38 560 kO 1 2 watt 5 QX503 121 01035 NPN Power supply reg R139 63 10244 30 270 k 1 2 watt 5 ulato...
Page 27: ...63 07784 1 kn 1 2 watt 5 R233 63 10235 72 1 kn 1 4 watt 5 RX508 63 10235 24 10 n 1 4 watt 5 R236 63 10235 40 47 n 1 4 watt 5 RX509 63 10235 84 3 3 kn 1 4 watt 5 R301 63 10243 06 1 8 n 1 2 watt 5 RX510...
Page 28: ...upon either the sweep scale factor See K and M or the scale factor See 0 G I and J o The channel 1 scale factor in volts V or millivolts mV E Indicates two signals summed together F Indicates inverted...
Page 29: ...Ground Lead Waveform Photograph Explanations Both photographs Figures B and C below show the same test circuit signal under the same conditions ex cept for ground lead length and positioning The phot...
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