When the flyback goes it often takes out the horizontal output transistor as well. Does anyone still sell flybacks for these? I also have one that went bad.
Bad solder on the flyback can cause these troubles also. It is worth trying to resolder the connections to save it.
Just be careful if you go into it! There are some deadly voltages in it- even when it is off. Best to leave it to someone who deals with these type repairs if you don't have the experience.
Some things go bad in the power supply circuits also sometimes. old capacitors can be issues in these monitors also.
mech