Vector The Black And White Monitor Faq And Guide

							Black & White Vector Monitor Guide  
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HIGH VOLTAGE (cont.) 
 
  
V2000 HIGH VOLTAGE 
 
The High Voltage PCB (in the metal cage with the flyback transformer). 
 
Zanen V2000 HV PCB Parts Location Part Number Upgrade Notes C900 1000 uF   50V radial capacitor   C901 1000 uF   50V radial capacitor   C904 47 uF       50V radial capacitor   C907 4.7 uF    160V radial capacitor   C908 4.7 uF    250V radial capacitor    
 
  
G05-801 REGULATOR BOARD 
 
The G05-801 Bottom Panel Regulator PCB. 
 
Zanen G05-801 Regulator Board Parts Location Part Number Upgrade Notes C102 1 uF 50V axial capacitor   C103 1 uF 50V axial capacitor    
 
NON-Zanen G05-801 Regulator Board Parts Location Part Number Upgrade Notes C100 7200 uF 50V capacitor   C101 7200 uF 50V capacitor   F100 5 amp slo-blo fuse   F101 5 amp slo-blo fuse    
 
  
						

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TROUBLESHOOTING  
 
Troubleshooting monitors requires experience, patience, and luck. The first step is to match the 
symptom the monitor displays to the diagnosis next to it in the “SYMPTOM-DIAGNOSIS” 
subsection.  This will pinpoint the circuit the problem is probably in, and often the parts to check. 
Next, the circuit should be visually inspected to see if there are any parts broken, burned, or if 
something is there that shouldn’t be, like a loose screw, etc. Some parts go bad before others, and 
should be checked first. In fact, following is the general order in which parts usually go bad: 
 
1. Semiconductors (like transistors, diodes, and integrated circuits). 
2. Fusible resistors. 
3. Electrolytic capacitors. 
4. Resistors. 
5. Capacitors and coils. 
 
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 picture tube or 
CRT, 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. 
 
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  
						

							Black & White Vector Monitor Guide  
Page 33 of 51 and a flash. The longer the monitor has been turned off, the smaller the pop and dimmer the flash. 
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. 
 
To maintain the safety and performance of the monitor, always use exact replacement parts. For 
instance, the wrong components in the power supply can cause a fire, or picture distortion may 
result from the wrong transistor being placed in the deflection circuitry. Component manufacturers 
offer specification sheets, which are useful for “mixing and matching”, but why go through all the 
trouble? Order exact replacement parts! Service your monitor on a nonconductive firm table like 
wood, NOT METAL, and take off all of your jewelry just in case. With all this in mind, you are 
ready to begin troubleshooting.  Observe the picture carefully. Try to vary the appropriate control 
that would most likely affect your particular symptom. For example, if there is poor brightness or 
no picture, try turning up the bright-ness or contrast control. If the controls have no effect at all, 
chances are there is trouble with the control itself, the circuit it controls, or a nearby circuit that 
may be upsetting voltages. Go to the list of symptoms and determine with the schematic where the 
bad circuit is. 
 
First, check for obvious visual defects such as broken or frayed wires, solder where it is not 
supposed to be, missing components, burned components, or cracked printed circuit boards. If 
everything looks good up to this point, make sure that diodes, electrolytic capacitors, and 
transistors have their leads connected in the right polarity as shown on the schematic and the circuit 
board. 
 
Turn on the power and measure the voltages at the leads of the active devices such as tubes, 
transistors, or integrated circuits. Any voltage that does not come within at least 10% to 15% of the 
voltage specified on the schematic indicates either a problem with that device or a component 
connected with it in the circuit. The next step is to use the ohmmeter to narrow down the field of 
possible offenders. 
 
To test a transistor, one lead of the ohmmeter is placed on the base; and the other lead placed just 
on the emitter, then on the collector. A normal transistor will read either high resistance (infinite), 
or little resistance (400 to 900 ohms), depending on the polarity of this type transistor. Then the 
leads should be switched, one remaining on the base, and the other switched from the emitter to the 
collector. Now the opposite condition should result: the resistance should be infinite if it was lower 
when the other lead was on the base. Consistently infinite readings indicate an open, and a short is 
demonstrated by 0-30 ohms on most of these test readings. Finally, place one lead on the collector, 
then the other on the emitter. No matter which lead is used, there should be infinite resistance. Any 
lower reading, such as 50 ohms (which is typical on a bad transistor), indicates a short. 
 
This all sounds pretty confusing, but a little experience on a good transistor will make you an 
expert in no time. Usually, the lowest ohmmeter setting is used for testing transistors. Once in a 
great while a transistor may check out good on this test, but may actually be “leaky” or break down 
only on higher voltages. If in doubt, change it. It is also wise to check the transistor out of the 
circuit just in case some component in the circuit is affecting the ohmmeter reading.  
						

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A diode is tested like a transistor except it only has two leads. Again, there should be high 
resistance one way and little resistance the other. If it tests bad, take one lead out of the circuit in 
case some component is messing up the ohmmeter reading. 
 
NOTE: DO NOT leave soldering equipment on the leads too long since all semiconductors, 
especially integrated circuits, are easily destroyed by heat. 
 
Without special equipment, integrated circuits are checked by verifying the proper DC voltage on 
the pins and the correct AC waveform using an oscilloscope. BE CAREFUL: Shorting their pins 
can easily destroy them. 
 
Resistors are checked with an ohmmeter and should usually be within ten percent of the value 
stated on them and on the schematic. You may have to desolder one lead from the printed circuit 
board. If you wreck the foil on the board, carefully solder a small wire over the break to reconnect 
the conductive foil. 
 
Capacitors are tricky. Their resistance goes up when checked with an ohmmeter, which shows a 
charging action. As they suck up current from the meter, the voltage goes up and so does the 
resistance. If you are sure a particular circuit is giving you a problem and everything else checks 
out O.K., Electrolytic capacitors are prime suspects. Substitute a new one and keep your fingers 
crossed. 
 
  
SYMPTOM DIAGNOSIS 
 
1. Insufficient width or height: 
A. Horizontal line (due to Y amplifier defection). 
· Bad yoke. 
· Bad Y amplifier output transistors. 
· Blown Y amplifier fuse. 
· Open fusible resistor in the Y amplifier. 
· Yoke pins not making good contact (very common). 
B. Vertical line (due to X amplifier defect). 
· Bad yoke. 
· Bad X amplifier output transistors. 
· Blown “X” amplifier fuse. 
· Open fusible resistor in the X amplifier. 
· Yoke pins not making good contact (very common). 
 
2. Picture spread out too far and/or crushed in certain areas: 
A. Controls for linearity (located on the deflection board and set at the factory) are 
misadjusted. 
B. Bad yoke. 
  
						

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Page 35 of 51 3. Poor focus: 
A. Low focus voltage from the high voltage board. 
B. Defective diode off the flyback. 
C. Defective focus control. 
D. Defective picture tube (CRT), although the chances of this are unlikely. 
 
4. Picture not bright enough: 
A. If the CRT voltages are present, the picture tube might be bad, although the chances of 
this are unlikely. 
B. Weak 90-volt supply from the EHT power supply. 
C. Loose wire to socket of CRT for G2 voltage. 
 
5. Silvery effect to the white lines, or picture looks dim, washed out: 
A. If the CRT voltages are present, the picture tube is probably bad. The surest way to cure 
this on an X-Y monitor is to replace the picture tube (CRT), although the chances of this are 
unlikely. 
 
6. Increasing brightness causes an increase in picture size and weakens focus: 
A. For the most part, this is normal in X-Y monitors. But if this should occur at normal viewing 
levels, either: 
· The CRT is defective (again, unlikely). 
· The high voltage rectifier is weak. 
· Or the high voltage circuitry has poor regulation. 
 
7. Picture rapidly blinks on and off: 
A. Internal short in the picture tube (arcing). 
 
8. A dot on the middle of the screen - Red LED is turned on (located on the deflection board): 
A. The X and Y signals are not making it into the monitor. 
B. Check cabling, jacks, and logic boards. 
C. X and Y amplifier failure. See Number 1 above and check the fuses first. 
 
9. Monitor won’t turn on: 
A. Open fuse(s). 
B. A defect in the power supply; check: 
· Fuse(s). 
· Transistors. 
· Open fusible resistor. 
C. Check jack to make certain all pins are obtaining their voltage from the other game circuitry. 
D. Check for loose foil, especially by D100. 
 
10. Blown 5 amp fuses: 
A. Caused by bad luck. Change fuses. 
B. If they keep blowing, check all power transistors that are heat-sinked on the side (as in 
the 19” version) or the bottom (as in the 13” version) of the monitor. 
  
						

							Black & White Vector Monitor Guide  
Page 36 of 51 11. Extremely bright picture; spider-web like retrace lines floating around on the picture: 
A. Defective Z amplifier circuitry; check: 
· The brightness and contrast controls. 
· For peeled foil on the deflection board. 
· Semiconductors, etc. 
B. See symptom 4, diagnosis B and C ONLY. A bad EHT power supply or loose G2 wire 
can cause the same thing. 
 
12. Hazy blob of light that shimmers on the screen. 
A. Open secondary on flyback winding. 
B. Failure of some component in the high voltage section. 
 
13. Corners of the picture are missing: 
A. Yoke is too far back on the picture tube neck. 
 
14. Picture is too far up, down, or not centered properly: 
A. Metallic yoke tabs-need to be adjusted. 
 
15. A shadowy image of the game remains on the screen, even after monitor is off: 
A. Picture tube has burnt phosphor. 
 
16. 2 amp fuses keep blowing: 
A. Check the large heat-sinked power transistors. 
B. Check D608 and D708 (1N4001) 
C. Check semiconductors, especially the transistors in the X and Y amplifiers. 
D. Bad yoke. 
 
17. Video information is distorted: letters and figures are “crinkly” - like crumpled paper, 
and it shakes slightly: 
A. Bad 90-volt power being supplied by the EHT unit. If everything looks good, check the 
electrolytic capacitors. 
B. The regulator control (R905) may need adjusting. 
 
On the Wells-Gardner 19V2000 monitor, the anode voltage is supposed to read 14.5KV High 
Voltage. That’s 14,500 volts with the beam current at zero. R905 adjusts this output voltage. To 
read this voltage, your meter needs a separate high voltage probe. Follow the directions 
EXACTLY as stated with the literature that comes with the probe. IF you don’t, or you touch 
something you shouldn’t, you’re dead. If this scares you, have someone qualified (a technician) 
perform this adjustment for you. Better SAFE than sorry. 
 
In the case of the Electrohome G05 monitor, the adjustment is complex and, of course, potentially 
DANGEROUS. Basically, the Electrohome anode voltage from the “flyback” and rectifier is 
supposed to be set at 12,000 volts with the beam current at zero. That’s right - THOUSANDS of 
volts! To read this voltage, your meter needs a separate high voltage probe.  Follow the directions 
EXACTLY as stated with the literature that comes with the probe. IF you don’t or you touch  
						

							Black & White Vector Monitor Guide  
Page 37 of 51 some-thing you shouldn’t, you’re dead. If this scares you, have someone qualified (a technician) 
perform this adjustment for you. Better SAFE than sorry. 
 
If you are still unsure, it may be best if you call Electrohome at (519) 744-7111 and obtain exact 
information from one of their staff engineers. [NOT LIKELY!] 
  
The following symptoms and diagnosis come from various people and sources. I cannot verify any of these will work for you. All references are made to the G05-802/V2000 monitor, unless specifically noted.  
 
If you have a scope, Electrohome has an EXCELLENT section in the manual showing you various 
test points on the boards and exactly what the scope trace should look like. 
 
First, you must verify that you are getting good signals from the game board. To do this, disconnect 
the 12-pin Molex connector at the monitor.  It has a pinout like this (use pin 11 to get oriented; pins 
1, 3, and 11 are shaped like a D instead of an O): 
 
1 2 3 4 5 6 7 8 9 10 11 12  
Flip the test switch inside the coin door and hit the reset button on the game PCB (or power cycle 
the machine).  This will put you into the test mode, which will draw a very stable, all white screen 
(white is ideal since the RGB values should be identical to each other). 
 
Set your meter for AC Volts and put the black lead into pin 8 of the game harness (this is a ground 
and should be black).  You should get readings similar to the following: 
 
G05-802/805 “Issue 4” Deflection Board  G05-802/805 “Issue 5” Deflection Board Pin # Description AC Voltage  Pin # Description AC Voltage 1 X Out 6.68  1 Z Out 6.70 2 X Ground 6.68  2 Y Out 6.69 3 Y Out 6.69  3 X Out 6.68 4 Y Ground 6.69  4 Ground Center Tap 0 5 Z Out 6.70  5 Y Ground 6.69 6 Z Ground 6.70  6 X Ground 6.68 7 30VAC Center Tap 30.3  7 30VAC Center Tap 30.3 8 Ground Center Tap 0  8 Z Ground 6.70 9 Ground Center Tap 0  9 6.3VAC Center Tap 9.70 10 30VAC Center Tap 30.3  10 30VAC Center Tap 30.3 11 6.3VAC Center Tap 9.7  11 Ground Center Tap 0 12 Heater Ground 3.0  12 Heater Ground 3.0  
						

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Bad game boards will usually have X/Y/Z Out = 0 VAC.  If you get 6-7 VAC on all of them, then 
your game board is probably OK. 
 
SPECIAL NOTE:  Omega Race games for some really strange reason do not use pin 12.  They 
have a separate wire soldered directly to the monitor board bypassing the connector and bridging 
the heater voltage from another point. 
 
  
Symptom: Fuses F100 and F101 blow on powerup. 
 
Test the diode bridge (DB100) with the monitor unhooked from the power input. The diodes take 
the AC and convert it to DC. If one or more are shorted you will get blown fuses. The diodes, or 
legs of the bridge should conduct one way, and be open the other way. Verify that b+ and b- are not 
shorted to ground. If the diodes are all good, both fuses should blow if there is a short. 
 
Check C100 and C101 for shorts.  If one or the other measures shorted, unplug the chassis output 
transistors and try again. The output stage transistors should be 2N3716 for Q708 and Q608 and 
2N3792 for Q709 and Q609.  Make sure they are the correct type, and make certain the transistors 
have the mica insulators installed. 
 
If C100 and/or C101 is still shorted, remove the shorted capacitor(s) and check to see if the fuses 
still blow. If C100 and/or C101 are not shorted, it could be an overload in the output stage. 
 
Unplug the yoke and power up the monitor without any input from the game board. Measure the 
voltage from chassis to F700 and F600.  It should be close to zero. If it is as much as 10 volts its 
not a problem (with the yoke unplugged the feedback loop isnt what it should be).  But if it reads 
something like 40 volts you have a bad driver stage. Look for Q706 to be shorted.  It is a MPSU57. 
  
Symptom: Screen Comes Up And Slowly Gets Bigger And Bigger. 
 
Probably a bad HV diode. That is a symptom of Low high voltage called blooming. Clean the 
connections of the transistors mounted on the outside of the high voltage cage before replacing the 
HV diode. 
  
Symptom: No Vertical Deflection; Spot Killer On. 
 
Check R100, R101 (if installed).  
  
						

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Symptom: Deflection Transistor(s) Continuously Shorts. 
 
On the V2000, a shorted D608 (“Y”) or D708 (“X”) will fry the pre-amps Q607 or Q706 
respectively. Replacing the shorted transistors will not help if the diodes are still bad. 
 
Also, check the transistors that drive the base of the shorted transistor. When a negative deflection 
transistor shorts it almost always shorts the one driving its base. 
 
This is also the symptom that is present if the X or Y signal coming off of the board is stuck (+) or 
(-). These signals will have to be tested while disconnected from the monitor. Ideally, you should 
check the game board outputs in the test mode with a scope. The game board outputs can be 
checked with a digital multimeter on the a/c scale if the game is NOT in the test mode. The reading 
while the game is in attract mode is one that is constantly changing, usually more than 1.5v but less 
than 3v. A game board output that is stuck positive or negative will read 0v a/c on a DMM. An 
output that is stuck will usually read +15 or -15 on the d/c scale. This condition must be corrected 
before the X and Y signals are reconnected to the monitor or that pile of shorted transistors will get 
pretty tall. 
  
Symptom: No Picture. Fuses On Deflection Board Test Good. Frame-Mount Transistors Not 
Shorted. Spot Killer Off. Neck Glows. Can Hear Vector Chatter.  
 
A bad HV diode most likely suspect here. There should be something like 400VDC going to the 
tube for the screen.  
  
Symptom: No Picture. F101 On Deflection Board Blows Instantly. Frame-Mount Transistors 
Not Shorted. Spot Killer Is Off. Neck Does Not Glow. No Vector Chatter Heard.  
 
This sounds like a bad/shorted diode on one of the four bridge rectifier diodes at DB100, or a piece 
of metal shorting the monitor mother board to the chassis, OR a transistor that is NOT insulated 
from the metal chassis. They all need an insulator and should show a relatively high resistance to 
the metal chassis.  
  
Symptom: Game Plays Blind. Spot Killer Is On. Raster Can Be Seen By Turning Up The 
Brightness. 
 
If you have screen brightness with the screen turned all the way up you can probably rule out the 
EHT voltage supply. 
 
Your problem sounds like a z-drive problem either from the main PCB or the monitor. 
 
Verify normal operation of the spot killer circuit by grounding the reset pin on the game board and 
you should hear the yoke chatter stop and the spot killer led on the deflection board will turn on.  
						

							Black & White Vector Monitor Guide  
Page 40 of 51 When you unground the pin, the led goes out, and yoke chatter resumes. This test is important 
because it eliminates 50 % of the circuits in the monitor that would give those symptoms, such as 
the deflection system. 
 
The problem could be a bad spot killer circuit (leaky transistors in the spot killer circuit).  Never 
bypass the spot killer, get it fixed right.  It will probably take an oscilloscope to track it down, or 
just replace the four transistors: Q500; Q501; Q502; and Q503. 
 
Chasing thru the Z-drive is easy after verifying proper operation of the HV board and deflection 
systems. Verify the HV system by checking the B+ voltage on pin 1 on the connector P500 to the 
deflection board. It should be 90-100 volts pulsed DC. If you do not have this voltage, the HV unit 
must be troubleshot. All of the outputs from the flyback are “geared” together. You can set the 
high-voltage by precisely setting the lower taps coming off the transformer. 
 
Verify that z-drive is coming off the game board.  (I am assuming you do not have a scope) The Z 
signal is a pulsed DC signal coming into the deflection board on a wire connected the board near 
R520 and R522 (it is marked “5” on the schematics). The side of the resistors closest to #5 wire is a 
test point. With the test pattern on the screen the z-signal will be 75% at 2Volts and 25% at 0Volts. 
You will read at least +1Volt at this test point with a voltmeter. 
 
If it’s dead 0, the problem is on the game board. 
  
Symptom: Game Plays Blind With Deflection Chatter. 
 
If you can hear deflection chatter, and the game plays blind, then there are two things you must 
check: (1) Low / no voltage to the tube filament; and (2) A failure in the HV supply. 
 
Look for the 6.3v AC heater filament voltage coming from the transformer block. This can be 
intermittent. 
 
With the monitor disconnected from the game board, I could measure a good 6.3v AC at the heater 
element with my meter, but when the monitor was plugged in, I got nothing under load. Leave the 
monitor connected and try and measure off the actual connector pins on the deflection PCB. Check 
the molex connector for good contact, as they can gum up causing intermittent contact. 
 
There is a fuse in the power supply that controls the 6.3 VAC for both the picture tubes heater and 
also the lamps in the coin door. It can weaken and create a nice voltage drop if it doesnt flat-out 
open.  
  
Symptom: No Picture. Spot Killer On. No Blown Fuses. R100 ‘Hot’. 
 
Check for a shorted diode in the bridge rectifier (DB1) and shorted filter capacitors (C100 & 
C101).