Star Tech Journal

May 1996
CD
WELLS GARDNER
S7.I on
CD-ROM
7000
OVER-VOLTAGE PROTECTION
T'SHOOTING
Every tech tip, game mod, test
procedure, Mfg change, update,
upgrade, precaution, etc.
for virtually all coin-op games
produced from
1979 - 1995
Every page (over 5,000!) of
STAR*TECH Journal
Now available on Disc!
CD-ROM technology:
Economical, Fast and Efficient!
Best Information Retrieval Available!
See Back Cover For Details
100 @'@e~
fi\o~ PeoP~ W/r\t}
To Pe~Feaf oN
I'@ WtteN
lHeY fltLoar
~ Jo~ Mfll.CMoN
Douglas "Enzo" McCallum
Shiawassee Technical Services
Lansing, Michigan
SYMPI'OM
A 7000 series Wells Gardner
monitor, with one end of DlO
removed (over voltage protect).
There is a vertical line in the cen-
ter of the monitor, no horizontal
deflection. With D 10 in circuit,
the monitor shuts down.
TROUBLESHOOTING
There are possibly two problems
in this Wells 7000. Check the B+
out of the main regulator, IC4.
Should be 123 V de or close.
Check it with a 'scope, it should
be CLEAN DC.
If it is high, all the flyback trans-
former derived voltages will be
also. This includes the 12 Volt
supply which is sampled through
D 10 for the shutdown circuit.
Bad power can cause shutdown,
but a loss of sweep could possi-
bly unload the power supply
enough to lose regulation.
open yoke (probably not), open
width and linearity coils (Ll and
L2). Most likely problem is bro-
ken solder on one of these.
Check C37, C38. With power off
should be continuity between
collector of HOT (horizontal out-
put transistor Q11) and position
adjust wire (through all the coils A
-check the schematic). Are yoke W
wires hooked up right (red and
blue for H)?
HAPP CONTROLS
Anos TOLL FREE
NUMBERS
WARNING
If you disable the shutdown, the
too-high voltages could be mak-
ing Xrays in the CRT. Don't
stand too close if you are plan-
ning a family soon.
Loss of horizontal sweep is usu-
ally straightforward. Look for
To receive your free copy of
Happ Controls products catalog, A
use the new toll free phone & fax •
numbers. Toll free Phone: 888/
BUY-HAPP (289-4277). Toll free
Fax: 800/593-HAPP (4277).