First, it's not the crt. Or, more precisely, I can't think of a plausible crt failure mechanism that could possibly cause what you see. But I can think of (and have seen) quite a few electronic failures that produce the symptoms you describe. So let's start with that as a working assumption for now.
I assume that you have the service manual, and have followed the procedure with no luck.
As you'll be working on a powered machine with its internals exposed, exercise due caution. Lethal harm can come to you if you are careless.
First, accurately mark the present settings of any control you intend to tweak. Convergence can be a tricky art, and having no known initial condition makes it unnecessarily hard.
Next, degauss the unit. Yes, there is an internal degaussing system, but it is relatively feeble, and takes many off/on/off cycles to do the job. Get a real demagnetizer and make sure that the unit is properly degaussed before attempting any convergence. It is also a good idea to maintain the mac's orientation wrt the earth while you work on it (to prevent spurious remagnetization). Needless to say, make sure that your adjustment tools are also nonmagnetic!
The fact that the E/W amp adjustment coil did nothing suggests a starting point. For example, if the coil has developed an open (either internally, or through a bad solder joint), it could very well produce what you're seeing. This theory is strengthened if you observe an ability to achieve reasonably good convergence on one half of the screen (by adjusting the E/W control on the crt neck assembly), but not both.
It's also important to note that the yoke's position along the neck affects convergence (so does the HV, for that matter, but if you don't have a HV meter, you'll be forced to consider other factors first). If the unit has been abused, the yoke can shift enough to induce a wide variety of ills. As a last resort, sliding the yoke backwards or forwards can often bring a Trinitron into convergence when all else fails. Before doing so, again mark the initial position carefully!
If investigation absolves the E/W amp coil, trace the circuit it connects to. Test the components that do so along the way. Inspect the traces and solder joints. Look for fried or discolored components. There's no substitute for a good, careful visual inspection.
I assume that you have the service manual, and have followed the procedure with no luck.
As you'll be working on a powered machine with its internals exposed, exercise due caution. Lethal harm can come to you if you are careless.
First, accurately mark the present settings of any control you intend to tweak. Convergence can be a tricky art, and having no known initial condition makes it unnecessarily hard.
Next, degauss the unit. Yes, there is an internal degaussing system, but it is relatively feeble, and takes many off/on/off cycles to do the job. Get a real demagnetizer and make sure that the unit is properly degaussed before attempting any convergence. It is also a good idea to maintain the mac's orientation wrt the earth while you work on it (to prevent spurious remagnetization). Needless to say, make sure that your adjustment tools are also nonmagnetic!
The fact that the E/W amp adjustment coil did nothing suggests a starting point. For example, if the coil has developed an open (either internally, or through a bad solder joint), it could very well produce what you're seeing. This theory is strengthened if you observe an ability to achieve reasonably good convergence on one half of the screen (by adjusting the E/W control on the crt neck assembly), but not both.
It's also important to note that the yoke's position along the neck affects convergence (so does the HV, for that matter, but if you don't have a HV meter, you'll be forced to consider other factors first). If the unit has been abused, the yoke can shift enough to induce a wide variety of ills. As a last resort, sliding the yoke backwards or forwards can often bring a Trinitron into convergence when all else fails. Before doing so, again mark the initial position carefully!
If investigation absolves the E/W amp coil, trace the circuit it connects to. Test the components that do so along the way. Inspect the traces and solder joints. Look for fried or discolored components. There's no substitute for a good, careful visual inspection.