The trouble is not in your tuner, it's in the set's vertical output circuit. A very common source of trouble is bad solder connections to the vertical output integrated circuit. When you wiggled the antenna connection before, it flexed the circuit board enough to get the connections working, but now it's not. A few minutes with a soldering iron very likely would get the picture back, although it's possible the IC itself has gone bad.
I believe that on the chassis in this set, the vertical output IC is an LA7832, mounted on a heatsink near the rear of the circuit board. I think it's marked IC421 on the board. If you or someone you know is comfortable with electronic soldering, you can try resoldering the connections.
Hi,
Your problem is not in the tuner. Since you have a sound but horizontal line only and when you bump the unit the video comes out, this is only indicated that you have a dry joints in the vertical section.
Re-soldering the cold solder on that area will cure the problem. Dry joints is hard to spot so you need to work with a good source of light. Vertical IC is located near the FBT and secured with the heat sink.
Hope it may help you.
Have a nice day.
Thanks for using fixya.
JDVillanueva
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