Star Tech Journal

Build A Monitor Test Station
(continued)
You can use a wooden board, a box, or whatever
works to attach the boards, power supply, and
the isolation transformer to.
to different monitors. Make sure you have an
earth ground hook up to connect to the monitor
chassis.
Then mount the switching power supply (re-
ferred to as SPS from now on) and the isolation
transformer. I mounted mine on the metal
mounting bracket as shown in figure 1. I also
mounted the AC end (plug, cord, line filter,
switch) and the push button on a front panel to
be mounted anywhere it's convenience for you to
use (under the bench, on the side of cart, or on
a box to take with you).
Then connect a RGB cable to 1J3 of the CPU/
video board and the RGB input of the monitor
under test.
OPERATION/TEST
Flip the AC switch on. When the picture comes
up, it will say "High score table reset, book-
keeping totals cleared, and factory settings re-
stored".
Wire the AC end (plug, cord, line filter, switch) as
shown in figure 1. Then attach the AC end to the
SPS and the isolation transformer as shown in
figure 1 (be sure to wire the earth or field ground
as shown in figure 1).
Attach one end of the push button switch to the
ground terminal of the switching power supply
(SPS) and the other end to 2J3.2 of the ROM
board.
Attach a wire from the SPS +5 volt terminal to
locations 2J2.6 and 2J2.4 of the ROM board,
and lJ 1. 7 of the CPU /video board.
Then attach a wire from the ground terminal of
the SPS to locations 2J2. l of the ROM board and
to lJl.2 and lJl.3.
Toe advance button works forward through the
tests, keep pushing it to get through the board
diagnostics until you get to the monitor test you
want. Works the same as all Williams video
games with the push buttons.
WHAT MONITORS WILL
Attach a wire from the -5 volt terminal (SPS) to
location lJl.9, of the CPU/video board.
Then attach a wire from +12 volt terminal (SPS)
to locations lJl.8 and lJl.5, of the CPU/video
board.
Now wire two long 16 gauge wires to the output
side of the isolation transformer. This will be
connected to the AC input of the monitor under
test.
I use a whole bunch of different AC monitor
connectors to interface the Monitor Test Station
IT TEST?
Toe monitor test station will work on the fol-
lowing monitors:
• Electrohome GO- 7
• Wells-Gardner 79XX's series
• Wells Gardner 49XX's series
• Pole Position monitors
• Any monitors with positive sync.
NOTES
You can add a 7404, to change it to negative
sync, if needed. With an adapter plug for the
RGB cable and a variac for the 100 Vac that
Nintendo monitors require, you can test
Nintendo monitors too.