Electrohome G08 Manual

G08 Vector Monitor FAQ & Guide Page 31 of 39   USING A G08-003 WITH COSMIC CHASM  
Cosmic Chasm uses the G08-105 monitor, which takes slightly different inputs and is basically a 
better version monitor than the G08-003. It is, however, hard as hell to find the G08-105 monitor.  
If you have a Cosmic Chasm game or boardset and it is missing this monitor, there is hope. 
 
The G08-003 can be substituted in place of the G08-105 (as can the WG6400 monitor, but that is 
an equally difficult monitor to find)....

G08 Vector Monitor FAQ & Guide Page 32 of 39  5) Using a short piece of wire-wrap wire connect the each pots #3 lead to the ICs #4 pin (-
15V).  
6) Connect a 90.1K resistor between pin #2 of the IC and #2 lead of the pot for each.  
 
Power up the boardset. Connect a scope to the RED color output on connector P2 pin 6. Note: all 
ODD numbered pins are GND. Adjust the pot attached to U29 so that the signal level swings 
between 0 volts and 4 volts. Repeat the adjustment for GREEN (U14) and BLUE (U15)....

G08 Vector Monitor FAQ & Guide Page 33 of 39   Appendix A: Parts Lists  
 
The Input Clamp Board is only discussed in the Preliminary G08-003/004 Service Manual. 
Included below is the parts list. Not all of these parts are necessary for a monitor rebuild, but are 
good to have on hand. 
 
Input Clamp Assembly Parts List Location Part Description Upgrade Notes D800 1N914   D801 1N914   D802 1N914   D803 1N914   D804 1N914   D805 1N914   D806 1N914   D808 1N914   Q800 2N3904   Q801 2N3906   Q802 2N3904...

G08 Vector Monitor FAQ & Guide Page 34 of 39    
The Current Limiter boards are attached to the deflection board and are only discussed in the 
Preliminary G08-003/004 Service Manual. Included below is the parts list. Not all of these parts are 
necessary for a monitor rebuild, but are good to have on hand. 
 
Horizontal Current Limiter Vertical Current Limiter Location Description Location Description D200 1N914 D250 1N914 D201 1N914 D251 1N914 D202 1N4935 D252 1N4935 D203 1N4935 D253 1N4935 Q201 2N3906...

G08 Vector Monitor FAQ & Guide Page 35 of 39   Appendix B: G08 SYSTEM REDESIGN  
 
Taken from a Sega/Gremlin Service letter: 
 
Gremlin/Sega reports that all of the problems encountered with the industrys first color X-Y game 
Space Fury have been identified and solved. 
 
The problems are centered around the deflection (X-Y) amps. Underrated power transistors 
combined with an extended on time during the power-up routine resulted in damaging the 
amplifier circuit. 
 
The remedy includes a modification...

G08 Vector Monitor FAQ & Guide Page 36 of 39   Appendix C: 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...

G08 Vector Monitor FAQ & Guide Page 37 of 39   Appendix D: Testing Transistors  
 
Most of the failures in the Electrohome G08 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...

G08 Vector Monitor FAQ & Guide Page 38 of 39    TESTING TRANSISTORS WITH A DIGITAL MULTI-METER 
 
Set your meter to the diode test. Connect the red meter lead to the base of the transistor. Connect 
the black meter lead to the emitter. A good NPN transistor will read a JUNCTION DROP voltage 
of between 0.45v and 0.9v. A good PNP transistor will read OPEN. Leave the red meter lead on the 
base and move the black lead to the collector. The reading should be the same as the previous test. 
Reverse the meter...

G08 Vector Monitor FAQ & Guide Page 39 of 39   REFERENCES  
 
1. The Wiretap Arcade Game Collectors Archive - http://www.spies.com/arcade/ 
Contains information about G-08 system games, as well as schematics for the monitor and game 
boards. 
 
2. Tac/Scan, Zektor, or Star Trek manual 
These manuals contain the most up-to-date information on the Electrohome G08-003 model 
monitor. 
 
3. Sega-to-Atari color XY circuit 
If you have given up on the G08, this is an alternative solution. 
 
4. Sega/Gremlin...