001 001 012 001 001 032 055 007 001 001 001 079 014 041 004 023 009 130 268 001 061 009 347

The video interface circuit is a general purpose RGB type input circuit. This circuit connects the external video signal to the video amplifiers. It can accept, DC or AC coupled positive going analog, negative going analog, and 4 line TTL. The particular mode of operation is selected by inserting jumpers, different value components, and solder bridges. The Production Assembly Drawings (PADs) are given in the appendix which describe the component differences. SIMPLIFIED VIDEO INTERFACE CIRCUIT...

2 Positive Going Analog Mode

In the positive analog mode, a bias current of .6mA flows to the input pin 2. This current is set by resistor I 261 I at the +Analog Enable input pin 11. The .6mA produces a voltage, across the parallel resistance of the game and I 288 I plus resistor 1278 I , at pin 2. If the external source resistance is 75 ohms, the black level voltage at pin 2 is .18V for 15KHz and .07 V for the 31KHz. The black level voltage is set by resistor divider I 223I & I 226 I to compensate for the bias current...

2093

Five Controls are located on a separate PCB for easy access. H SIZE--------------Horizontal raster size V SIZE---------------Vertical raster size V RAS. POS.-----Vertical raster position H POS-------Horizontal picture position M GAIN---------------------Master gain The board Controls are located on the main PCB Focus and G2 on the FBT. Optional board Controls are pincushion, video black level, and horizontal hold control. 5. Image Horizontal linearity Vertical linearity Pincushion

254

The sync interface comparators are biased to .15 volts, by resistors 323 & 327 , to permit receiving low level sync signals such as RS170. For low level composite sync, the vertical and horizontal lines are tied together and jumper 328 is left off. For normal amplitude sync, (greater than 2.3 volts) resistors 315 & 326 form an attenuator to protect the sync interface comparators and normalize the sync amplitude. This combination also reduces noise sensitivity since the sync voltage...

5

In the + analog AC coupled mode, the video black level is set by a clamp circuit which is active during the first part of horizontal sync. For this circuit to work properly, the incoming video must be at the black level voltage when horizontal sync starts and remain blanked for at least 4.5uS. The clamp circuit is dependent on the polarity of incoming horizontal sync. For separate horizontal sync, the sync polarity should be positive. For composite sync, and positive going horizontal sync...

About This Manual

This manual is specifically written to aid the service technician, repairing CERONIX Models 1493, 1793, 1993, 2093, 2793, and 3693 color monitors. To understand how the Monitor works, it is best to know what each circuit does and how each circuit relates to the other circuits. The Block Diagram is presented in a simplified view and a comprehensive view to accomplish the goal of understanding the whole unit. Once the general picture is clear, the complexity of each circuit will be easier to...

Attach The Grounding Strap First

With the degaussing coil leads centered on the bottom of the CRT, FORM THE COIL to avoid the remote control board. INSTALL A WIRE TIE through INSTALL A WIRE TIE through the top hole in the left CRT ear. the top hole in the right CRT ear. INSTALL WIRE TIES through the bottom hole in the left CRT ear. INSTALL WIRE TIES through the bottom hole, with the grounding strap spring, in the right CRT ear. Degaussing Coil & Grounding Strap Attachment Specification. For The Model 1793, 1993, 2093 Video...

Crt Auto Bias And Auto Bright Circuit Description

The beam current feedback circuit uses a PNP video transistor 954 to direct most of the beam current to the auto bias circuit while passing the voltage waveform, from the video amplifiers to the CRT cathodes. Diode I 958 I and capacitor I 956 I insure that no video waveform distortion occurs. An additional benefit of this circuit is that it protects the video amplifiers from the destructive arc energy. Resistors I 948 I and I 955 I divide energy due to CRT arcing, between the video amplifier...

Crt Auto Bias Vertical Sync

The vertical oscillator one shot (LA7851 pin 16) supplies the start timing for the auto bias vertical sync. This signal is conducted to the emitter of 379 by jumper 089 . The base of 379 is connected to the retrace boost pulse by resistor divider 3831 and 384 . Combining these signals in this way produces a collector waveform which has the vertical oscillator one shot timing and is dependent on the retrace boost pulse. For the 15KHz case, transistor 100 inverts the vertical oscillator one shot...

Dynamic Focus Circuit Function And Circuit Description

The dual focus CRTs require a waveform on the 2 focus grid. This voltage waveform is dependent on the position of the beam on the CRT. The lowest voltage part of the waveform is in the center of the screen and the highest voltage part of the waveform is at the corners of the screen. The dual focus CRTs require a waveform on the 2 focus grid. This voltage waveform is dependent on the position of the beam on the CRT. The lowest voltage part of the waveform is in the center of the screen and the...

Equipment setup for trouble shooting the Iso Xfr75W Iso Xfr100W Isolation Transformers

SAFETY FIRST Use only one hand when working on a powered up ISO XFR-75W, ISO XFR-100W to avoid electrical shock. Always wear safety glasses when working on powered up electronic equipment. Note When using this isolation supply for working on monitors, it is important to have some resistance (10MQ or less) to ground. An insulated monitor connected to a insulated power supply may attain a high static voltage. When this voltage discharges through the ISO XFR-75W, ISO XFR-100W control circuit, the...

Fr205 853

L ten Sie zwei kurze bussleitungen zu den Heizfadenanschlu stiften weich. 2. Benutzen Sie schwarzes Band, um die Fotozelle ber der Bohrung im Plastik-CRT-Einfa ung Stecker zu sichern. Vorsicht Seien Sie sicher, die Fotozelle nicht zwischen die zwei Tests zu verschieben. 3. Speichern Sie die Gleichstromspannung, die von der Fotozelle mit dem Monitor ausgegeben wird, der normalerweise l uft. Der Monitor Mu laufen damit 10 Minuten die Heizfadenspannung messen. 4. Drehen Sie weg den Monitor Ab. 5....

Isolation Transformers

The ISO XFR-75W -100W MUST be grounded by mounting on a grounded, conductive surface via at least two screws. WARNING Mains power and ground connections must be made before power is applied to the ISO XFR-75W or the ISO XFR-100W Isolation Transformers. WARNING FOR CONTINUED SAFETY, REPLACE SAFETY CRITICAL COMPONENTS ONLY WITH MANUFACTURER'S RECOMMENDED PARTS (REFER TO SERVICE LITERATURE). AVIS POUR MAINTENIR LE DEGRE DE SECURITE DE L'APPAREIL NE REMPLACER LES COMPOSANTS DONT LE FONCTIONNEMENT...

Power Supply Test

To verify that the power supply is working correctly, connect the 17V line, as indicated in section 2 on this page. Also connect the oscilloscope GND to V- and the oscilloscope probe to the FET drive (anode of diode 116 ). There should be a waveform at this point. If there is no FET drive waveform, check the voltages and waveforms on the C5184 pins and compare them to the voltages and waveforms on the schematic. Connect the AC power cord with the AC voltage, from the variable transformer turned...

Tc Z

The high voltage in the CRT, through an arc, can be conducted to any tube socket connection on the video board. To reduce the danger of these arcs causing component failure, a number of arc current paths are provided. The tube socket has integral spark gaps which conduct arc current to the tube ground (aquadag). through dissipation resistor 882 . The clamping voltage of the spark gaps to the cathodes and G1 is about 1.5KV. The peak arc current to the video amplifier outputs is limited by...

Vertical And Horizontal Sync Circuit Description

Composite sync or separate vertical and horizontal sync are buffered by two comparators in the sync interface circuit. A vertical sync synchronization circuit is used to insure a stable raster and functions as a sync separator. The synchronization circuit is bypassed, for interlaced vertical sync, because this circuit rejects the half horizontal line time variation used to generate the interlaced vertical raster.

Vorrichtungen haben zum Lsen von Problemen mit dem 75W und dem 100W Isolierung Transformatoren benutzt

SICHERHEIT ZUERST Um elektrischen Shock zu vermeiden, benutzen Sie nur eine Hand beim Arbeiten auf einem angeschaltenen Transformator 75W oder 100W. Tragen Sie immer Sicherheitsgl ser beim Arbeiten auf angeschaltener elektronischer Ausr stung. Anmerkung Beim Benutzen dieser Isolierung Versorgung von Monitoren dem Bearbeiten zu, ist es wichtig, irgendeinen Widerstand zu haben, (10 Meg.Q oder kleiner) zu erden. Ein Isoliermonitor, der an eine Isolierenergie kann angleschlossen wird eine hohe...

W

A +12V regulator is used to supply current, to all the control circuits in the monitor, with the exception of the power supply. Many of the control circuits are decoupled from the +12 volt line with a resistor or diode to minimize noise from common current loops. The Over Voltage Protect circuit is built into the power supply and monitors the flyback transformer peak pulse voltage. This circuit will turn off the power supply and hold it off if the EHT exceeds its maximum rated value. Since...

Wire Routing Instructions

Attach the protective earth, Fold remote cable to clear green yellow, ground wire. CRT and add wire tie. Rout G2 wire around CRT socket, shorten with loop, and add wire tie. Plug in video board. Fold video flat cable to avoid contacting the metal frame. Secure fold with a wire tie. Shorten focus wire and add wire tie. Finished assembly with the different voltage type wires not touching each other. Make solder connection CA when using these C PRAs for replacement parts on the XX92 product line....

Circuit Function Description

The basic function of the ISO XFR-75W and ISO XFR-100W is to isolate the line power for monitors requiring an isolation transformer. The transformer is designed to have a low leakage flux value which allows it to be mounted close to the CRT. To accomplish the low leakage flux, the transformer has two sets of primary and secondary coils mounted on a modified toroid type core. The ideal transformer would be a toroid but this type transformer is expensive because it is difficult to wind. A relay...

Ceronix Model 1793 Replacement

The CRT Auto Bias IC is a combination of digital and analog circuitry. The digital part is a counter and control logic which steps the analog circuits through a sequence of sample and hold conditions. The analog part uses a transconductance amplifier to control the voltage on a 10uF capacitor (one per gun). This voltage is buffered and sent to the video amplifiers as the bias voltage. In monitors without CRT auto bias, this voltage is adjusted manually using a setup procedure to set the color...

Horizontal Raster Width Control Circuit Description

The purpose of the horizontal width control is to 1. Provide a convenient means for adjusting the horizontal raster size. 2. Correct pincushion distortion in the vertical axis. 3. Correct horizontal raster distortion caused by periods of high beam current. The horizontal width control circuit is comprised of two main parts The control circuit and the diode modulator (DM). The control circuit combines four signals in the monitor to produce the width control circuit. These signals are 1....

High Pot Tester

The MONITOR is connected to the enclosure ground via the signal cable, monitor support hardware, and the protective earth ground wire. The chassis ground must be connected to earth ground. All the large accessible metal parts are connected to ground. Highpot, F r Schock Gefahren, StromkreisBeschreibung. F r die Modelle 1493,1793,1993,2093,2793, und 3693 videomonitoren. Es ist die Verantwortung der Firma, die den Ceronix Monitor in dort system benutzt, sich zu vergewissern, da kein Schock...

Simplified Power Supply Circuit Description

The FET drive circuit avoids this problem by sensing flyback diode conduction. If the flyback diode conduction is sensed, the low current start mode is selected. This mode turns the FET on, to a current of .1A, for not more than 4uS. If before or during the low current FET on time, the flyback diode breaks free, and the FET drain voltage goes down, the flyback diode voltage comparator will signal the regulator to permit the FET to be turned on for a full power cycle. The cycle after the last...

Ceronix 2793 Service Manual

SAFETY FIRST Use only one hand when working on a powered up monitor to avoid electrical shock. Many of the failures that cause burnt components and boards are eliminated by the load sensitive switching mode power supply in the CERONIX monitor. This feature can cause problems with servicing the monitor if the proper trouble shooting approach is not used. The equipment setup, shown here, is necessary for efficient trouble shooting of the CERONIX monitors....

2pl Cpm2013

Plugs in main board left side of flyback transformer. Degaussing Coil amp Grounding Strap Attachment Specification. For The Model 2793 and 3693 Video Monitor. 1. The first item to attach to the picture tube is the grounding strap. Lay the tube face down on a soft surface. Slide the folded over end of the braid over the left top CRT mounting ear. Attach the spring at the other end to the, right side top, slot in the rimband. Pull the bare wire through the bottom slot in the...

Installation Instructions For The XX93 Monitors

A 3 amp slow blow fuse for the degaussing current and a 75 VA isolation transformer are the minimum requirements for using our monitor in a product. 3. Install the monitor in the enclosure. Refer to the installation instructions supplied by the system manufacturer for details of mounting the monitor in the enclosure. 4. Connect the green yellow ground wire to the earth ground connection on the enclosure. This wire is connected to the ground screw, located on the monitor chassis behind the...

Table Of Contents

Block Diagram Crt Monitor

Video Amplifier Circuit, Function, Video Amplifier Circuit Description and Video Board Power Supply and Arc Protect CRT Auto Bias and Auto Bright Circuit, Function, CRT Auto Bias, Auto Bright, and Vertical Sync Delay Circuit Description 72 CRT Auto Bias and Auto Bright Monitor, Block Diagram Blanking, Master Gain, and Fault Circuit, Function, Blanking, Master Gain, and Fault Circuit Blanking, Master Gain, Beam Limiter, and Fault Vertical and Horizontal Sync Circuit Vertical Deflection Circuit...

2 Year Limited Warranty

This product is warranted by CERONIX to be free of defects in material and workmanship for a period of two years from the date of purchase. All parts and labor are free of charge during the warranty period. This warranty does not cover mechanical breakage due to physical abuse. It is the customer's responsibility for shipping the defective unit to and from CERONIX or one of the authorized service centers for repair. Please attach a note describing the problem. CERONIX Inc. 13350 New Airport...