WG 25K7197 with 6-7" vertical sweep

[Mike Johnston]

Hello. I have a Wells Gardner model 25K7197 in a Big Buck Hunter conversion cabinet.
Symptom:
The vertical sweep has collapsed ( after a move ) to about 5 to 7 inches and has a slight wave.
The vertical size adjustment and the VR9 have very little effect.
Things I have done:
I installed all 17 electrolytic capacitors from Lizardlick Amusements ( no change ).
I replaced DC blocking capacitor C50 ( no change ).
I re-soldered the CRT socket on the neck card ( long shot, no change ).
Can  you make any suggestions ?
I have a schematic.
Other than a VOM I do not have any test equipment.
Mike J.

[Kevin Mullins]

As with any K7000, check the chassis carefully for bad solder joints and traces that may have lifted and crack especially around large resistors and such.

Check for +24v at IC3, check R91.

Replace IC3

[qrz]

closely inspect the vert yoke connections. i.e. look for a broken wire.

the vertical windings are two identical coils wired in parallel.
when either side is open, the symptom is what you posted...

hopefully , it will be a single break and easily patched.
with multiple breaks , just replace the yoke