Vector The Black And White Monitor Faq And Guide

							Black & White Vector Monitor Guide  
Page 41 of 51 You might try unplugging the high voltage supply and see if that cools things down.  Also check 
the fuses. F100 and F101 should be 5 Amp slow-blow.  F700 and F600 should be 2 Amp fast-blow. 
F102 should be 1 Amp slow-blow. 
 
If the fuse values are all correct, try unplugging the output transistor connectors (P700 and P600).  
If unplugging either of those helps, check the output transistors that connect to those connectors.  
They are mounted on the chassis. 
  
Symptom: No Picture. Spot Killer is Off. Game Plays Blind With Deflection Chatter. 
 
Check the female connector connecting the HV cage to the deflection board. 
  
Symptom: Monitor Powers Up, Spot Killer On. If The Brightness Is Turned Up, A Complete 
Screen Is Seen, But It Looks Like A Spider Web. 
 
Check and replace as necessary the brightness or the contrast pot. Also check for bad solder joint, 
or a bad tantalum capacitor in the spot killer circuit. 
  
Symptom: Picture Will Come And Go. 
 
My 19V2000 had a bad contrast pot and I could jiggle it to get/loose the picture. Try messing with 
it to see if it needs replacing.  
  
Symptom: No 6.3v at P900. 
 
Check for cracked solder joint(s) on the connector.  
  
Symptom: Image Has Ripples Or Zigzags. Vectors Are Wavy. 
 
Either of these symptoms could point to either regular wirewound resistors being used instead of 
the non-inductive wirewound resistors in the yoke feedback circuit (yoke to ground) OR a bad filter 
capacitor allowing high-voltage power supply noise to get back into the deflection circuits.  If your 
deflection board does not have R100 and R101, then there is probably too much ripple on the 
power supply for the monitors deflection circuit. Check the small filter caps on the monitor board 
(C102 and C103). 
  
						

							Black & White Vector Monitor Guide  
Page 42 of 51  
Symptom: Slight Vertical Size Changes Back And Forth In The Picture. 
 
This is often caused by a flaky linearity POT on the monitor deflection board. With a Wells-
Gardner V2000, the vertical adjustment is at R600. The Electrohome G05 has four POTS instead of 
two, with vertical adjustments at R600 and R602.  
  
Symptom: Fuzzy Picture. 
 
The picture getting fuzzy implies fading capacitors. Replace all the capacitors in the HV cage. Get 
low ESR and 105-degree capacitors. These cost a little more, but are well worth it.  
  
Symptom: Picture Is Faint, or Has A Slight Glow. 
 
If your game uses a black light (Asteroids Deluxe or Omega Race), the black light can actually 
energize the phosphors in the CRT.  Installing some automotive UV tint over any exposed areas of 
the tube should eliminate your problems. 
  
Symptom: Always Have A Bright Dot In The Middle Of The Screen. 
 
The contrast should do about the same thing as a Black Level control. I have seen monitors where a 
dried out capacitor in the black level/contrast area has caused similar symptoms.  
 
Using a scope, you should be able to start at the Z out on the game board and make sure you have 
some good variability (full range swing) of the signal. Follow it through the monitor and see where 
the signal compresses/expands into being turned on all the time. 
  
Symptom: Image Too Bright. 
 
Check the electrolytic capacitors to make sure none have been put in backwards. 
  
Symptom: Resistor R610 Is Fried. 
 
Check R620 and Q603. If necessary, replace R620 with a 20-Ohm 7W wirewound resistor. 
  
Symptom: R613 and R618 Are Fried. 
 
Check to be certain that none of the leads (including the heatsink) of Q606 or Q607 is shorted to 
ground. Also check D606 or D607 to see if they have opened. This would crank all the currents up 
and destroy R613 and R618.   
						

							Black & White Vector Monitor Guide  
Page 43 of 51  
Also check for bad solder joints or a hairline crack in a trace. I would check the pins that connect to 
the large transistors mounted on the side REALLY closely. I would also do a continuity test on all 
the pins. 
  
Symptom: No Picture. Neck Glows. Damage To C100, P701 And C102. Fuses Blow. 
 
Check the chassis transistors for shorts. If one is shorted the right way (emitter to base) or 
(collector to base) it will destroy the new deflection board when you power it up. (they usually 
short all 3 together). 
 
You must also verify that the X and Y outputs from the game board are not stuck (+) or (-). This 
will damage any monitor you plug into it. 
  
Symptom: Adjustment Of The HV Pot In Both Directions Does Nothing To Affect Brightness. 
 
This is frequently caused by poor solder connections on the connectors on the deflection and HV 
boards.  
  
Symptom: No Picture On The Screen. HV Was Present, But The Heater Would Not Light 
Up. 
 
(text by Matt McCullar August, 1989): The G05 has separate supplies for heater and high voltage, 
so I checked the 3-amp slo-blo fuse in the transformer heater circuit. Removing the fuse, and using 
the continuity function on my DMM, the fuse looked good. The heater inside the neck of the CRT 
had not opened up, and was also good. With no fuse in the circuit, I got 6.3 volts A.C. from the 
transformer, which was normal. But every time I reconnected everything, the voltage to the heater 
dropped about 3 volts. I checked all the wiring and it was good. 
 
I did run across one interesting thing: the coin door lamps use the 6.3 volts A.C. to light up, and 
their sockets appeared a bit faulty, so I cut their wires and took them out of the circuit. But that did 
not help light up the picture tube’s heater. 
 
I finally got a break a few days later when the heater fuse blew. When I replaced it, the heater came 
on! What happened? I concluded that the fuse’s internal resistance had increased, thereby dropping 
the voltage across it. Instead of blowing the way it should have, this [fuse] just weakened. I didn’t 
notice this before because the beeper continuity function on my DMM turns on the beeper when it 
finds anything under 30 Ohms across the meter leads. Ideally, a fuse should be close to zero Ohms 
(although some fuses with very small current ratings are about 10-Ohms), but this fuse had 
apparently slowly increased to several times what it should have been. Since its overall resistance 
had not yet gone over 30-Ohms, however, the beeper on my meter turned on and I assumed the fuse 
was good. So now when I check a fuse, I don’t use the continuity test, and instead get a direct 
resistance measurement.  
						

							Black & White Vector Monitor Guide  
Page 44 of 51  
G05-801 troubleshooting information 
(from Atari’s “The Book”) 
 
 
G05-801 Power Supply Board 
 
The following procedure is for the +25 volt power supply. Components in parentheses are for the 
–25 volt power supply. All voltage measurements are to the chassis. 
 
  
Symptom: Fuse 100 (101) open 
 
Check bridge rectifier DB100 for shorted diodes. Check capacitor C100 (101) for short. Check 
ZD100 and ZD101. 
  
Symptom: 25VDC measures 40V 
 
Zener diode ZD100 (101) open. Check Current Limiting resistors R102 and R103. 
  
Symptom: 25VDC is too low 
 
Measure the voltage on the emitter of the transistor 0100 (101). Should read 40V. If this voltage is 
30V or less, capacitor C100 (101) is open or one diode in DB100 bridge rectifier is open. 
 
Remove the two screws holding the transistor Q100 (101) to the heat sink. Measure the base 
voltage. If 27V, replace Q100 (101). If less than 27V, Zener diode ZD100 (101) is defective or 
capacitor C102 (103) is leaky. 
  
Symptom: 25VDC is too high 
 
ZD100 or ZD101 is open. Check the Current Limiting resistors R102 and R103.  
  
Symptom: CRT Neck is Dead 
 
Check resistor R104 
  
						

							Black & White Vector Monitor Guide  
Page 45 of 51  
G05-801 High-Voltage Board 
 
 
Symptom: Fuse open (F900) 
 
This may be a matter of adjustment. Locate the high-voltage adjustment pot R912 (next to Q901). 
Rotate it completely clockwise. Replace fuse and apply power. Place positive lead of meter on pin 
5 (gray wire) of the harness input connector P900. Slowly turn the high-voltage adjustment until 
the meter reads 90V. If the fuse opens again, check the following components. 
 
Opens: ZD900, ZD901, and Q901. Shorts: Q900, Q902, Q903, and ZD903. 
  
Symptom: 90V measures less than 80V 
 
Measure the voltage on the anode of the Zener diode ZD900 or the emitter of Q901. Should read 
9V. If less, replace the diode. 
 
Locate resistor R901 near the top edge of the board between Q900 and 0901. This 1.2K-ohm 
resistor stands up about a half inch off the board. Place positive voltmeter lead on the resistor lead 
closest to the edge of the board. 
 
Voltage Reading Probable Cause   9V Q901 shorted Less than 15V ZD901 shorted, or Q900 or Q902 has low gain 25V Open Q900. Q902, Q903, R906 or T900  
If all components are OK, the oscillator circuit (Q903) may be loaded down by a defective 
component in the secondary of T900. With an ohmmeter, check the following components for 
leakage: D903, C909, C906 and C907. 
 
The other components D901, D902 and the doubler cannot be checked with an ohm-meter. Use the 
following procedure instead. Note: When working with the doubler, always make certain that the 
CRT anode is discharged to ground! Unsolder the wire going from the high-voltage transformer to 
the terminal of the doubler. Apply power and measure the 90V (pin 5 of R900). If the 90V comes 
up, replace the doubler. To determine if D901 or D902 are loading down the oscillator, unsolder 
one end of the diode and note if the 90V actually measures 90V. 
 
  
G05-801 Deflection Board 
 
Missing information can either be caused by the logic (game) PCB or the X-Y amplifier. The 
easiest approach is with an oscilloscope. However, a scope is generally not available on location.  
						

							Black & White Vector Monitor Guide  
Page 46 of 51 Follow the steps listed below to determine which is the faulty board. The Y measuring points are in 
parentheses. 
 
Missing X (Y) information 
1. Set your voltmeter on “AC” and on the 10-volt scale. 
2. Measure the voltage at pin 1 (3) of P703. The meter should read 4.5V +/- 1V. If less 
than 3.5V or even zero, the game PCB is defective and the monitor is probably OK. 
3. Measure the voltage at pin 2 (3) of P702. The meter should read 4.5V +/- 1 V. If zero, 
check for open fuse F700 (F600). This is a small pica fuse located near the side of P702. 
Replace with a 2-amp, fast-blow fuse. 
 
If the fuse is OK and the voltage is low, check Q705, Q706, Q707 and Q708 (Q605, Q606, Q607 
and Q608). You could swap the +X driver transistor Q708 with the + Y driver transistor Q608 to 
see if the problem follows the transistor. Similarly, the -X (Q707) and -Y (Q607) can be swapped. 
 
Z Amplifier 
Proper adjustment of the brightness and contrast controls is the same as for the raster-scan monitor. 
 
1. Turn both brightness and contrast controls to minimum. 
2. Turn up brightness until picture is barely visible. 
3. Turn up contrast for desired picture. 
 
Problems related to the Z amplifier are few. Remember! Make sure all power supplies are operating 
and that the filaments in the picture tube are glowing. 
  
Symptom: Black screen 
 
Turn up the brightness control. One of three symptoms will appear: no picture, a dot in the middle 
of picture, or interconnecting lines between objects. Proceed to troubleshoot, based on what 
appears: 
  
Symptom: No picture 
 
R515 or brightness control (R516) is open. 
  
Symptom: A dot 
 
If the red LED (D507) is on, proceed to X-Y amplifier procedure. 
Interconnecting lines 
 
If the red LED (D507) is on, check the following components for shorts or open circuits: D504, 
D505, D506 and C510. 
  
						

							Black & White Vector Monitor Guide  
Page 47 of 51 If the red LED is off: 0504 is open, Q503 is shorted, contrast control R526 is open or there is no Z 
input from the game PCB. 
 
  
G05-801 Transistor data 
 
Alrighty, then, let’s look at the schematics for the G05-801 monitor. Q701 and Q702 is a 
differential amp powered by Q703, a constant current supply. Q703 is being run at about 3.6 mA 
(0.65 volts through 180 ohms). Q701 and Q702 normally share this current equally, so about 1.8 
mA average through each of those. 
 
Maximum voltage drop across Q703 (assuming +35 and -35 power supplies) would be 20.74 volts 
(35 - 0.65 through R704 - 0.65 volt drop at Q701/Q702 emitters - 12.96 volts drop across R740).  
Power dissipated in Q703 is about 75 mW.  So Q703 needs to be able to handle 20.74 volts, 3.6 
mA, and 0.075 Watt. Good design practice would be to have Q703 handle the ENTIRE power 
supply of 70 volts (but for that much voltage to be present there would have to be multiple failures 
happening at the same time -- unlikely to happen, 35 volts is sufficient but would also represent 
failures happening elsewhere), at least double its operating current - 7.2 mA, and at least double its 
operating power - .15 watt. So for our purposes, anything that can handle the voltage rating will do. 
Even if it can’t handle the voltage R740 will protect it from destruction. 
 
Now for Q701 and Q702. Current is 1.8 mA average, 3.6 mA peak. Voltage peaks out at 35.65, 
averages 33.85 (1.8 volts dropped through collector resistor). Average power is 60 mW. Once 
again, current and power are insignificant and the main spec here is voltage. 
 
Speed of Q703 doesn’t matter, but you want something fairly fast in the Q701 and Q702 positions. 
 
What does it all mean? Use a fairly fast (over 1 MHz) NPN transistor with good gain in the 1-5 mA 
range and a voltage rating of at least 40 volts (the more the merrier). Whatever you use - USE THE 
SAME PART FOR BOTH Q701 AND Q702. Why? You want these two as close to matched as 
you can get. Most important matching is emitter to base voltage. If these aren’t the same you get 
something called “offset voltage” which will cause centering to be off. With no offset voltage, zero 
voltage from the game board will give you zero current through the yoke (and that’s a good thing!). 
  
						

							Black & White Vector Monitor Guide  
Page 48 of 51  
WHAT TO DO WHEN YOU DON’T KNOW WHAT TO DO  
If you are totally confused about where to begin to hunt for a problem, and can’t find the problem 
in the “SYMPTOM DIAGNOSIS” subsection, there may be another way to proceed. 
 
Take a VOLTMETER and (if possible) an oscilloscope and begin probing the jacks. You can start 
with the input jack to the monitor. Using the oscilloscope, make sure both the “X” and “Y” 
information is present (which it isn’t during the “SOUND” test). 
 
NOTE: It is advisable to use one of the games test patterns (obtained when you put the game into 
the Self-Test mode) when using the oscilloscope. The simple diamond one is a good choice. This 
way the “X” and “Y” information at the above jack isn’t changing and a recognizable waveform is 
easy to see if it’s there. The DC voltages tend to jump around like crazy when the game is being 
played or is running through its ATTRACT mode, so, using the test pattern tends to keep them still. 
 
Next, use the voltmeter to make sure the other voltages are present at each pin. Similarly, you 
proceed to P500 on the deflection board, and P900 on the EHT unit to make sure all the correct 
voltages are present. Use the schematic to determine what the correct voltages should be. 
 
Check the pins on the CRT to be sure the voltages are getting this far. If everything looks good to 
this point, perhaps the CRT is bad. DO NOT check the anode voltage unless you have a special 
high voltage probe or you may wind up repairing X-Y monitors in heaven. 
 
DO NOT BE FOOLED by the silent operation of the monitor. Regular T.V. sets and monitors buzz 
and crackle a lot when they’re operating - this is normal, for them. BUT, Vector monitors are 
noiseless unless something is wrong. 
 
Whatever you do, ALWAYS read the literature that comes with any test equipment you use so that 
you will not damage the equipment, the monitor, and most of all YOURSELF. 
 
Quite a few of the parts between the Electrohome and the Wells Gardner monitors may be 
swapped. The CRT’s for example are completely interchangeable. Also, many of the transistors 
used in each monitor are the same. Certain critical components in the power supply and the EHT 
unit are dangerous to interchange. The best thing to do is to compare both monitors’ parts lists to 
see if the descriptions of any two particular parts you want to swap match exactly. Substitution 
manuals are available for transistors and semiconductors, but you never know about them. 
Sometimes they work and sometimes they don’t, depending on the critical circuit parameters. If in 
doubt, order exact replacement parts. 
 
 
 
  
						

							Black & White Vector Monitor Guide  
Page 49 of 51 Appendix A: Common Ground Connections  
 
 
From: John Robertson  
Newsgroups: rec.games.video.arcade.collecting 
Subject: TechTIP: How to make VECTOR MONITORS very RELIABLE! 
Date: 22 Oct 2001 
 
 
It’s been a little while since my last Tech Tip, but this is something that’s been on my mind for a 
while now, and a posting in the Vector mail-list got the following response from me...: 
 
Vector monitors blow up because the ground reference for the monitor drifts relative to the logic 
boards (MPU and video) when the power supply connections overheat. This will then bias the input 
signals offset enough to overdrive the outputs. Hence my argument for chucking the original power 
supply and putting in a switching supply.  I started doing that about ten years ago and have not lost 
a single Electrohome/Sega monitor since. I assume this also kills Tempest/Star Wars/Major 
Havoc/... monitors etc. Those pesky grounds get a few ohms resistance and all sorts of nasty things 
happen.  
 
I first discovered this on Gottlieb pinballs over ten years ago-the ground for the regulator would 
overheat the pin/wiper contact which would become a small resistor and thus the ground of the 
MPU would drift up relative to the cabinet ground, which also happened to be the ground path for 
the driver transistors. When the MPU ground would change to about 0.5 to 0.7VDC above cabinet 
ground the base of the transistors would then start to conduct as the MPU would be trying to turn 
off the transistors, but the Emitters are tied to the cabinet ground. Hence the transistors would start 
to conduct... You will recall that transistors generate far more heat when they are used at the 
beginning of their working range rather when they are switched completely on and off as in regular 
vector monitors (or solenoid drivers, etc.). So in a little while, it croaks. No obvious cause...replace 
the transistors and everything works. For now... 
 
So get VERY GOOD GROUND (COMMON) CONNECTIONS BETWEEN THE MONITOR, 
MPU AND POWER SUPPLY for reliability!!!!!!!!!!!!!!!!!!!!!!!! Solder fat conductors with nasty 
heavy gauge connectors between each component in the system.  Put in healthy SWITCHING 
SUPPLIES! 
 
Happy vectors will result. 
 
John :-#)# 
 
  
						

							Black & White Vector Monitor Guide  
Page 50 of 51 Appendix B: Testing Transistors  
Most of the failures in the Electrohome G05 or Wells-Gardner V2000 monitor (as is the case with 
most electronic devices) are semiconductor failures, specifically, the transistors. All transistors 
discussed in this document can be tested in the same way; it does not matter if they are the large 
chassis-mounted transistors or the tiny PCB-mounted transistors. With the transistors out of circuit, 
set your multi-meter on Rx1K scale and use the following procedures. 
 
NOTE: ANALOG AND DIGITAL MULTI-METERS REQUIRE DIFFERENT TESTING 
PROCEDURES FOR TRANSISTORS! Digital meters always show infinite resistance for all 6 
combinations (if you accidentally get your skin involved it will show something around 2M Ohms). 
The best way to test transistors with a DMM is to make use of the diode test function, which will 
be described after the analog test. For both methods, if you read a short circuit (0 Ohms or voltage 
drop of 0) or the transistor fails any of the readings, it is bad and must be replaced. 
 
Why do Digital Voltmeters read open circuits on diodes and transistors? 
 
Because of the ability to use amplifiers, DVM can use much smaller voltages to check resistance. 
For the most part this is a good thing. It allows you to check resistors in circuit, without turning on 
things, like transistors. 
 
Diode junctions (which there are two of in a transistor) do not “turn on” until they reach 
somewhere around 0.4 ~ 0.7 volts, depending upon what they are made of, and a lot of other stuff. 
In a way, diode junctions are similar to neon light bulbs, they act like open circuits until the right 
voltage is reached, and then they act like shorts, until the voltage drops below the critical threshold. 
Without proper current limiting, the diode junctions explode. The thing about diodes is that they 
only do this in one direction, if you switch the test leads, they do not conduct at all.  (Well, until the 
voltage gets much higher, and then it is a bad thing. ;^) 
 
Sometimes you want to be able to “turn on” the diode junctions (to test them), so DVMs have a 
“Diode” test mode.  This places enough voltage on the test leads to turn on the diode junction.  The 
number you read on most meters is the actual turn on voltage threshold across the diode. 
  
TESTING TRANSISTORS WITH AN ANALOG OHMMETER 
 
For type NPN transistors, lead A is black and lead B is red; for type PNP transistors, lead A 
is red and lead B is black (NOTE: this is the standard polarity for resistance but many multi-
meters have the colors reversed; if the readings do not jive this way, switch the leads and try it 
again). Start with lead A of your multi-meter on the base and lead B on the emitter. You should 
get a reading of 2.5K Ohms. Now move lead B to the collector. You should get the same reading. 
Now try the other 4 combinations and you should get a reading of infinite Ohms (open circuit). If 
any of these resistances is wrong, replace the transistor. Only 2 of the 6 possible combinations 
should show a resistance and that value should be 2.5K Ohms; none of the resistances should be 0 
Ohms (shorted).