Vector The Black And White Monitor Faq And Guide
Have a look at the manual Vector The Black And White Monitor Faq And Guide online for free. It’s possible to download the document as PDF or print. UserManuals.tech offer 3 Vector manuals and user’s guides for free. Share the user manual or guide on Facebook, Twitter or Google+.
Black & White Vector Monitor Guide Page 1 of 51 The Black & White Vector Monitor FAQ and Guide Version 1.1 February 7, 2002 Table of Contents INTRODUCTION....................................................................................................................2 THEORY OF OPERATION...............................................................................................4 MONITOR TYPES..................................................................................................................9 HIGH VOLTAGE BOARD...............................................................................................13 DEFLECTION BOARDS...................................................................................................14 TUBE AND YOKE................................................................................................................21 ADJUSTMENTS.....................................................................................................................23 INSTALLING A CAP KIT................................................................................................26 TROUBLESHOOTING.......................................................................................................32 WHAT TO DO WHEN YOU DON’T KNOW WHAT TO DO....................48 Appendix A: Common Ground Connections............................................................49 Appendix B: Testing Transistors.....................................................................................50
Black & White Vector Monitor Guide Page 2 of 51 INTRODUCTION Note: Very little, if any, of this document is my own work. Information in this document has been taken from official factory manuals, technical updates, practical experience by others, etc. In many instances I have paraphrased or omitted information from the original documents for readability and/or clarity purposes. I thought it would be helpful, not only to myself, but to others having trouble with their B&W vector monitors. I would strongly suggest downloading and reading through the color vector monitor FAQ and Guide as it will also enlighten you to the world of vector monitors. Please read through this entire document before working on your malfunctioning monitor, and make sure you have a set of schematics on-hand. Also, in order to properly test your vector monitor, it is imperative that you have a known-working game board and power supply to provide a good input signal to the monitor. A bad game board and not the monitor can actually cause some of the symptoms of a ‘bad’ monitor. DISCLAIMER CAUTION!!! LETHAL VOLTAGES ARE PRESENT IN ARCADE MONITORS. SUITABLE PRECAUTIONS SHOULD BE TAKEN BEFORE ATTEMPTING TO SERVICE YOUR MONITOR. REMEMBER, NO WARRANTIES, EXPRESS OR IMPLIED, ARE GIVEN. USE THIS INFORMATION AT YOUR OWN RISK. I AM NOT RESPONSIBLE FOR ANY DAMAGES THAT MAY OCCUR TO YOUR PERSON OR PROPERTY. Acknowledgements The following people have contributed to the development of this document (knowingly or otherwise): Marc Alexander, Tom Baddley, Roger Boots, Mark Davidson, Mike Haaland, James Hagen, Mark Jenison, Al Kossow, Noel Johnson, Matt McCullar, Phil Morris, Jon Raiford, John Robertson, Mark Spaeth, Andy Warren, Andy Welburn and Gregg Woodcock. (let me know if you want to see your name here – or don’t want to!)
Black & White Vector Monitor Guide Page 3 of 51 What Is A Vector Monitor (taken from the Bally/Midway Omega Race manual) Welcome to the world of the X-Y monitor, an electronic device that strikes terror into the heart of many a technician. The main reason it is so intimidating is that the Vector, Quadrascan, or X-Y monitor is TOTALLY UNLIKE the Rasterscan monitor or T.V. set as you probably call it. Since many technicians are generally unfamiliar with the circuit operation, they may not be able to figure out when a symptom correlates with (points to) a particular circuit. If you are a technician, this section of the manual will certainly be a lifesaver (our modest opinion). If you don’t know anything about electronics, just relax because these monitors are a lot simpler than a regular monitor or T.V. set. Vector or X-Y monitors are used because a regular Rasterscan monitor constructs the picture in a different way. For example, your T.V. set has 525 horizontal lines on the screen from top to bottom. Each line is a slice of the picture. If you stare real close at the edge of a picture of a curved object (a large ball) or an angular object (the peak of a roof) on the screen of your T.V., you will be able to see the individual slices that the objects edge is made up of. The edge of the curved or angular objects will not appear to be completely smooth but will look like they are stepped. However, at normal viewing distance, these same curved or angular lines will appear to be smooth or straight and not stepped. To make sure that the pieces or slices of the picture stay together just like they were transmitted, T.V. sets have synchronization circuits. Vector monitors don’t use ANY of this. Here, the electron beam smoothly goes anywhere it is told to paint the picture. It DOES NOT go across the screen 525 times to paint the picture in slices. Because of this shortcut, the circuitry is less complex and the detail in the figures will appear smoother. One drawback is that the brightness level is intentionally designed to be at a level high enough to burn or etch right into the picture tube face. This will be covered in more detail later in this section. If your X-Y monitor develops a problem, you can go directly to the “SYMPTOM DIAGNOSIS’ subsection where you can match up your problem to the problem described and the circuit that may be causing it. From there you go to the schematic diagrams for your particular brand of monitor and troubleshoot the circuits mentioned in the “SYMPTOM DIAGNOSIS” subsection. If you are a technician who is unfamiliar with X-Y monitors, you may want to read the “THEORY OF OPERATION” subsection first. This section IS NOT a rigorous description of circuit operation, but a simplified general description of major circuit blocks. Some literature has been written on this subject. Electrohome’s instruction and service manual on the G05-801 is an analysis on one X-Y monitor (which Midway Mfg. Co. does not use) described from an engineering standpoint. All that is necessary to understand it is a battery of U.N. interpreters. Electrohome’s instruction and service manual on the G05-802 and G05-805 monitors (which Midway Mfg. Co. does use) is simpler and more condensed. The best manual we have found on the subject so far is Wells Gardner’s publication on their Graphic Display Unit, model 19V2000 (which Midway Mfg. Co. also uses). Most technicians will understand it and it is very complete. The above manuals are available on request from your distributor or monitor manufacturer. [not likely]
Black & White Vector Monitor Guide Page 4 of 51 THEORY OF OPERATION To understand what goes on inside the monitor, large general groups of circuits will be examined instead of laboriously analyzing the branches and small circuits that make up these groups. This will help avoid confusion and aid in a basic, concrete, knowledge of what makes up a monitor. CAUTION!!! LETHAL VOLTAGES ARE PRESENT IN THIS MONITOR, SUITABLE PRECAUTIONS SHOULD BE TAKEN BEFORE ATTEMPTING TO SERVICE YOUR MONITOR. DEFLECTION PCB THE POWER SUPPLY The best way to begin explaining the innards of the X-Y monitor is at its beginning or the inputs to the monitor. Ignoring the ground or common tie points for many of the components, which represents zero voltage, there is 30 volts AC going into P100 - the input jack. The AC input is fused by F100, F101 and applied to bridge rectifier DB100. The 30 volts AC means the voltage and current alternate or jump up and down going positive and negative with zero voltage in between. DB100 and the capacitors immediately after it make up the power supply. Most of the circuits in the monitor can’t use power that jumps up and down since your picture would do the same thing. DB100 chops up the waveform and capacitors C100 and C101 build up the power that DB100 chops up. The capacitors roughly filter the power and then leak it out so the power is smooth and not varying. R100 and R101 serve to limit inrush current to the filters and offer some protection to DB100 in case of a fault condition. Typical operating voltages are +/-34V. If any component fails in the circuit, the usual result is blown fuses, burning in this area, or just less power. The power supply starts the whole ball rolling, but remember that other circuits build up voltages that can be tapped for those circuits that need more than this thirty plus thirty volts AC from the game transformer. The DC voltage to the high voltage supply is taken off before the current limiting resistors and is separately fused by F102. The EHT supply voltage is isolated from the main filter ripple component by D100. With the EHT supply functional, a normal operating voltage at P500-10 would be +40V. THE “X” AND “Y” AMPLIFIERS Let’s go back to the input jack, P100, again. Along with the grounds and the two 30 volt AC inputs is the “X” and “Y” channel video information. The “X” input is about 10 volts AC and the “Y”
Black & White Vector Monitor Guide Page 5 of 51 input is about 7.5 volts AC. The “X” channel information represents parts of objects from LEFT to RIGHT on the screen. The “Y” channel information represents parts of objects from TOP to BOTTOM on the screen. To get complete objects, then, you MUST have both the “X” and “Y” inputs. If this is so, then why aren’t the input voltages equal? Well, notice how a T.V. tube is shorter than it is wide? The up and down voltages (“Y” input = +/- 7.5 volts AC) don’t need as much as the side-to-side voltages (“X” input = +/- 10 volts AC). If we divide the picture into four quadrants, the responsibilities of the X and Y amplifiers may be seen more clearly: -X and +Y information +X and +Y information -X and -Y information +X and -Y information So let’s say your monitor only has the right side of the picture and the left side is missing. The top and bottom right of the screen has “+X”, “+Y”, and “-Y” information. The left side has “-X”, “+Y”, and “-Y” information. But since the right side is O.K., obviously the only information missing is “-X”. Therefore, there’s got to be a problem somewhere in the “X” amplifier. From P100, the “X” or “Y” signals each go through a resistor and the linearity control of their respective channels. The Wells Gardner V2000 monitor only has one linearity control per channel while the Electrohome G05 monitor has two linearity controls per channel. These controls are supposed to be set at the factory. But sometimes they need additional adjusting. The best way to do this is to get a test pattern on the monitor screen, remove the glue holding the control adjustments in place, vary the controls until the size is right and the lines are nice and straight, and then re-glue the control adjustments so they cannot move. After the linearity controls, the rest of the circuitry just corrects the signal for the picture tube and then amplifies it. The output power transistors (two for each channel) are heat-sinked on the bottom or the side of the monitor chassis. These feed the “X” and “Y” signals in the form of current to the yoke. The yoke then puts out two invisible electromagnetic fields or forces. These fields pull the stream of electrons that is spit out of the neck of the picture tube to the various quadrants of the monitor screen where they will write or paint a picture. Just as you may use a magnet to pull nails across a table, so does the yoke’s magnetic field pull the electron beam all over the picture tube screen to write the picture. The “X” and “Y” information we talked about earlier is what tells the electron beam WHERE to write or paint the picture. When the electron beam hits the phosphor coating on the backside of the front of the picture tube or screen, the phosphor glows in proportion to the electron beam intensity. In other words, the more electrons in the beam, the brighter the light that comes from the screen of the picture tube where it is being hit by the electron beam. This varying beam intensity is the function of the “Z” amplifier.
Black & White Vector Monitor Guide Page 6 of 51 The amplified signal is applied to a cascade stage formed by Q605, Q606 and then applied to the basses of output transistors Q608, Q609. These transistors are operated class B in an emitter follower configuration. Current is coupled through F600 to the yoke and then to ground through the sense resistor R620. Very heavy feedback is applied from R620 to the base of Q603, to correct for any non-linearities in the amplifier. A considerable amount of power supply ripple can be tolerated because of the push-pull arrangement of the output transistors and the canceling effect of such a stage on any common ripple component. R621 serves as a critical yoke-damping resistor. THE “Z” AMPLIFIER From P100, the “Z” amplifier signal voltage is sent to the base of Q504 in the “Z” amplifier circuit. This circuit amplifies the AC “Z” signal and is then sent to the cathode of the picture tube. This varying “Z” signal voltage in turn varies the intensity of the electron beam producing at least eight different amounts of brightness or “eight gray scale steps” as the engineers would say. Transistor Q504 forms a common emitter amplifier. A TTL compatible brightness signal is applied by means of P100-5. An amplified and inverted replica is present at the collector and this is applied to the CRT cathode. AC gain (contrast) is controlled by R514 and fixed resistor R513. Transistor Q503 is normally biased on very hard by means of R511, R512 and may be treated as a low value resistor that plays no significant part in active amplification of the signal. Brightness is controlled by varying the DC potential at G1 of the CRT, by means of R517. Diode D506 and C504 isolate and hold the cathode voltage high during power down to prevent phosphor burn. At the same time as the 90 volt line is decaying, the bias for Q503 is lowered, turning the transistor off and further retarding the discharge of C504. THE SPOT KILLER If the “X” and “Y” signals are missing, or there is a 90 volt DC power failure - from the high voltage circuitry that feeds the “Z” amplifier, or if any other missing signal condition should occur, the “spot killer” circuitry comes on to effectively turn off the electron beam thus keeping the phosphor from being burned. At the same time, the light emitting diode turns on informing you of this. The deflection signal is sampled for rate of change and amplitude on both channels, by means of R500, R501, C500, C501 and then rectified to form a negative holding voltage on C502, C503. This negative voltage holds Q500 and Q501 off. There is no current flow through Q502 and LED D504 is not lit! When the sampled signal falls below minimum requirement then the positive voltage applied by R506, R507 turns on Q500, Q501. This causes Q502 to conduct, allowing the LED to light up and apply sufficient positive voltage to the emitter of Q503 to cut the transistor off, thereby blanking the display.
Black & White Vector Monitor Guide Page 7 of 51 If the “spot killer” didn’t come on when any of the above conditions exists, the electron beam wouldn’t be moved around and the phosphor in the center of the screen would be burned from the intense electron beam that is hitting it without moving. Transistors Q500 through Q502 and their circuitry affect the voltages on Q503 to turn the beam current off. This DOES NOT mean you have automatic protection against CRT burns from too much brightness. In fact, it would probably be a good idea to keep the brightness and contrast controls TURNED DOWN to the point where the game looks good but not too bright. If the picture is way too bright, fine spider web-like retrace lines will follow the figures wherever they move and you are headed for a burnt CRT. The brightness control affects the DC voltage between the cathode and G1 of the picture tube. The contrast control varies the amount of signal to the cathode. Both control picture intensity. THE HIGH VOLTAGE GENERATOR - OR - EHT SUPPLY The High Voltage circuit can be broken down into two basic subsystems, the regulator and the high voltage generator. On the side of your monitor is a box-like cage with a wire that goes to the CRT. This is the EHT supply. It performs several functions, one of which is to supply the high voltage for the CRT. The input to the EHT supply is at pin eight of P900 where 40 volts AC is fed through a large resistor, R900. Actually, this is a VERY important resistor because it limits, or regulates, the current to the oscillator, keeping it from taking off on its own and increasing the high voltage to the point where X-rays are emitted from the CRT, which is DEFINITELY NOT GOOD. The primary function of R900 is to limit the high voltage generated under a regulator failure condition. It also serves to limit dissipation in Q900. The high voltage supply is isolated from the main ripple component of the primary filters by D100 and C900. The high voltage generator is a free running Hartley oscillator that operates at approximately 30KHz. Did we mention an oscillator? What’s an oscillator? Well, in this case, it is made up of: transistor Q903, the primary winding of the “flyback” transformer (T900), and a few other components that toss the voltage back and forth (oscillate) 25,000 times each second. By doing this, it electromagnetically induces a bigger voltage in the “flyback” transformers secondary winding since it is bigger. This voltage is rectified (chopped up) by diode D904 to get 12,000 volts DC in Electrohome monitors and 14,500 volts DC in Wells Gardner monitors. This voltage is used to light up the CRT (picture tube). The other transistors, from Q900 to Q902 and their circuit components keep the power to the oscillator steady or regulated, as they say in engineering. There is an adjustment control, R905, to make certain the oscillator is fed the proper power. The “flyback” transformer also has an additional secondary winding, which generates more voltage to power other circuits. At pin three of P900 there is about 400 volts DC for focus voltage to the CRT. This can be adjusted with R909, the focus control. From pin five at the other side of the “flyback” transformer secondary winding, there is 90 volts DC for the “Z” amplifier circuit. In between pins three and five of P900 there are two diodes and capacitors that change the AC from the “flyback” secondary winding to DC just like the power supply. In fact, that’s just what it is, a “mini power
Black & White Vector Monitor Guide Page 8 of 51 supply’. All of the secondary diodes are fast recovery to operate at the 30KHz oscillator frequency. Using normal diodes are a definite way to fry your flyback! THE CRT - (PICTURE TUBE) The CRT has already been described indirectly. However, to make a picture or turn the CRT on, certain voltages are needed. Otherwise it won’t work. These are: about 6 volts AC (note that’s AC) is needed for the heater filament in the tube neck to light up; the electron beams intensity must be controlled by the “Z” amplifiers signal which is applied to the CRT’s cathode; there must be voltage at G1 of the CRT for brightness; there should be about 400 volts DC at G2; there should be focus voltage which varies but can go as high as 400 volts DC; and there should be high voltage at the anode of the CRT which runs into the thousands of volts (this voltage can jump almost one inch through the air - so BE CAREFUL!!) Always remember that a monitor can bite like a snake. Even when it is turned off, capacitors hold voltage and will discharge it to you should you be touching chassis ground. The CRT or picture tube, itself, is a giant capacitor, so avoid the flyback anode plug hole. With the monitor on, the power supply circuit and/or the flyback, which puts out at least 12,000 volts, CAN BE KILLERS!! Avoid handling power transistors (usually output transistors), yoke terminals, and other high power components when the monitor is on. WARNING: That picture tube is a bomb! When it breaks, first it implodes, then it explodes. Large pieces of glass have been known to fly in excess of 20 feet in all directions. DO NOT carry it by the long, thin neck. Discharge its voltage to ground by shorting the anode hole to ground. Discharging a CRT Do not forget to discharge the CRT - even if you are just going to be unplugging the socket from the neck of the CRT (i.e., to gain access to another part). A tube that has some air in it can deliver a nasty shock back out of the neck pins. You should NEVER short the anode of the tube DIRECTLY to common ground. ALWAYS use a resistor of 1 Meg ohm between the anode (underneath the suction cup) and common ground. A direct short without the resistor will cause the HV Rectifier Diode (D903/D904) to fail. A 1 Meg ohm, 3W resistor should be sufficient. I would recommend using a High Voltage Probe to discharge the monitor. This is the safest method, as the probe is designed to withstand extremely high voltages (hence the name, right?). Lacking an HV probe, you can use this tried and true method, be it a little more dangerous. Use a plastic handled screwdriver; connect one end of a wire with an alligator clip at each end to chassis ground and the other end to the metal shaft of the screwdriver. Be certain you have a 1 Meg ohm resistor somewhere in your connection. Using ONE HAND ONLY (put the other in your pocket) and touching ONLY the plastic handle of the screwdriver (DO NOT TOUCH THE METAL SHAFT) stick the blade of the screwdriver into the anode hole. Be prepared for a fairly loud pop and a flash. The longer the monitor has been turned off, the smaller the pop and dimmer the flash.
Black & White Vector Monitor Guide Page 9 of 51 But BE CAREFUL, picture tubes will hold a very healthy charge for at least a week if not longer. Even after you’ve discharged it once, it may still carry a residual charge. It’s better to be too careful than dead, which is why electronic equipment always carries stickers referring servicing to qualified personnel. Handle the side with the viewing screen against your chest when changing it. ALWAYS wear safety goggles when handling the picture tube. MONITOR TYPES G05-801 vs. G05-802 vs. G05-805 vs. 19V2000 vs. 15V2000 vs. LAI vs. HOEI vs. Hantarex The terms vector, vectorbeam, quadrascan and X-Y get tossed around quite liberally. There are a number of different vector monitors – both color and black & white. While some are compatible, many are not and can have disastrous results if the wrong monitors are substituted. Note that while the Cinematronics/Vectorbeam vector monitors are monochromatic (i.e., black & white) they cannot be substituted for any other type of monitor. The Electrohome G05-801 is the 19” B&W vector monitor that originally came with Atari’s Lunar Lander and early versions of Asteroids. The G05-801 monitor has two PCBs with large black heatsinks on the right side of the chassis. The G05-801 monitor expects an input voltage of either 56VAC or 74VAC. The G05-802 is the second revision of the monitor and is much more common. The G05-802 expects a 60VAC input. A third version of the black and white vector monitor, the V2000, was made by Wells-Gardner and is plug compatible with the Electrohome G05-802. In fact, a vast majority of the G05s and V2000s are bastardized monitors with parts from each tossed in, so it is really hard to tell what version of the monitor you might have. A G05-801 is not plug compatible with a G05-802 or V2000 monitor. The G05-801 has two plugs (power and signal) while the 802 and V2000 has just one molex plug connector. The G05-805 is a 15” version of the G05 vector monitor. Aside from a physically smaller picture tube, the monitor is effectively identical to its larger brother – the G05-802. There is also a 15 version of the V2000. It is called the 15V2000 and, along with the Electrohome G05-805, were primarily used in cocktail and cabaret vector games. Many distributors in Australia, in an attempt to reduce the initial shipping cost games, sourced vector monitors locally. That company, Leisure & Allied Industries, made a unique black & white vector monitor design, producing both 14” and 20” monitors. The LAI monitors are NOT plug compatible with any Electrohome or Wells-Gardner vector monitors. I have precious little information on the LAI vector monitors and this document will not focus on them for that reason. HOEI vector monitors were used in Alcas bootleg of asteroids (called ‘Planet) as well as other bootlegs of Star Castle and Asteroids. [note: the bootleg Star Castle games had the DACs on the game boards so they could use a ‘standard’ B&W vector monitor instead of the specialized Cinematronics monitor.]
Black & White Vector Monitor Guide Page 10 of 51 All the Atari Italian-built vector games - Battlezone and Asteroids, used a vector monitor produced by Hantarex. The Italian-built Elettronolo Star Castle bootleg (Stellar Castle) also used a Hantarex vector monitor. There were some (factory?) conversion kits for Atari’s Football that had you swap the yoke, HV and deflection boards, and play Asteroids on a 25” tube. Does anyone have any further information on this? Game Monitors Used Lunar Lander Upright G05-801 Asteroids Upright (up to serial 18,900) G05-801 Asteroids Upright (serial #s above 18,900) G05-802 Asteroids Cocktail G05-805 Asteroids Deluxe Upright G05-802 and 19V2000 Asteroids Deluxe Cocktail & Cabaret G05-805 and 15V2000 Red Baron Upright and Cockpit G05-802 and 19V2000 Battlezone Upright G05-802 and 19V2000 Battlezone Cabaret and Cocktail G05-805 and 15V2000 Omega Race Upright and Cockpit G05-802 and 19V2000 Omega Race Cabaret G05-805 and 15V2000 Various games in Australia LAI-KZ series Asteroids Bootlegs (mostly UK) HOEI Italian-built Asteroids & Battlezone Hantarex Using a Color vector monitor in place of a B&W vector monitor If you have an extra Wells-Gardner 6100 color vector monitor (and who doesn’t), you can use it as a substitute for a G05-802 or 19V2000. However, you will need to make a harness adapter that converts the 12-pin molex attached to the cabinet harness into a 15-pin molex plug that the Wells- Gardner 6100 expects. The following information is taken from the Wells-Gardener 19K6100 manual: “This (color) display differs very little from that used in Atari’s black-and-white X-Y video games, such as Asteroids, Battlezone, or Red Barron. The only major difference is that it now has three Z amplifiers to control the three color guns. If you service this color display on a test bench, use only the power supply assembly for Color X-Y Games. You cannot use standard line voltage or a power supply from a black-and-white X-Y game such as Asteroids, since the voltages produced by those sources will damage the Wells-Gardener color X-Y display”. The good news is the color power supply will plug right in place of the B&W one and it’s beefier.