Vertical deflection lost on TV

Image is a single horizontal line going through the middle; classic case of no vertical deflection, right?

I’ve heard numerous suggestions, but they’re pretty worthless without pics. “Check for bad components”? Fine, but WTF do they look like? “Check for dry joints”? Okay, how the hell can I tell if the joints are dry? What do dry joints look like?

For example, I’m told that the “service switch” may be in the wrong position, but where is this “service switch” and what does it look like?

I got this TV for free from a stranger, so no idea what may or may not have been done to it before, so who knows if the previous owner attempted to repair it and just left the service switch to the wrong spot, or whatever.

If you don’t know the answer to those basic questions or even understand what the questions mean, you have no business poking around inside a TV.

I’ll never learn if I don’t start somewhere.

I’m very conservative in my handling of things, it’s not like i go around randomly plugging and unplugging parts of the TV. Currently, I’m not even doing really anything except looking, since I dont want to do anything physically until I have some idea that there’s an action I can perform that’s potentially useful. My thinking is that there may be some very simple action I can perform such as flipping the aforementioned service switch.

I know about keeping the TV unplugged, and I know that the picture tube is under very high voltage, and that capacitances must be discharged even long after the tv is unplugged.

True enough, but I’d strongly suggest starting with something slightly less dangerous than a TV.

However, since you appear bent on trying anyway, you ought to start here and get a grasp of the fundamentals. If you still have questions later, I’ll be happy to answer them.