Star Tech Journal

0
STAR*TECH Journal
1990
1991
1992
• 1993
MONITOR UPDATES
All monitor articles
covered in 1990 or
1991 or l 992 or
1993 published in a
handy easy-to-reqd
format.
Over 25 new video
monitor Symptoms
and Fixes in each.
These tips previ-
ously appeared in
STAR* TECH Jour-
nal's Volume 11, 12,
13 or 14. Update
your technical
library with these
valuable
references.
October 1993
WELLS GARDNER
K7000
No HIGH VOLTAGE
Michael Babin
Palisades Amusements
Las Vegas, NV
SYMPTOMS
Wells Gardner K7000 series. No high voltage. B positive too high:
140 to 160 Vdc. High voltage shut down.
SOLUTION
Note: All checks done with no power to monitor.
• Check fuse Fl
If Fl is open, replace it -but don't apply power to monitor yet.
• Check Qll horizontal output transistor for short.
Place your digital meter to Diode Check mode. With the positi
(+) lead of your meter to ground and negative (-) lead to the
collector of Qll. The collector of Qll is the tab mounted on the
heat sink. If Qll shows shorted before you pull it out, check
capacitor C36 for short. If shorted, replace it with Wells Garner
part #046x0551-003.
• After you replace C36, recheck for shorted condition of Q 11. If
it's okay, then ...
• Check the voltage regulator (IC4) between pins 1 and 4-should
read on your meter about .184 with the positive lead on pin 1 and
negative lead on pin 4. If shorted replace it.
MONITOR AT THIS POINT SHOULD START UP.
add $3.50 s/h
Order
Prepaid or COD
S*TJ
PO Box 1065
Merchantville, NJ
08109.609/662-1080.
• With monitor running, check B positive IC4 pin 4 -should be
between 123 V de and 130 V de.
• If monitor runs, then shuts down after about 5 minutes -replace
D18 damper diode even if it checks okay.
This should solve most all your high voltage problems on th~
monitor.