I've got an RCA F27689, built in 2001. Not the world's best 27" TV,
but decent enough for me right now.

I'm a bit of a tweaker, so I've already found out how to get into the
service mode of my TV. I'm also a fairly cautious type, so I also
wrote down all the default values for my set before attempting to mess
with anything. I've also read some horror stories that suggest if
you're going to be fiddling with things in the service menu, you'd
best be prepared for the consequences of messing something up
permanently (or at least enough to require a visit to a service
technician). You may consider me a fool, but the potential benefits of
tweaking make that a risk I'm willing to take.

Using a Digital Video Essentials test pattern as a guide, I can see
that some parameters make visible changes: I've found vertical
position, vertical size, and horizontal position, for example.

However, the one thing I really want to change -- horizontal size, to
correct for what I feel is an awful lot of horizontal overscan -- has
thus far eluded me. I'm beginning to think maybe it can't be adjusted
at all (!), but I don't really want to believe that just yet. I'm
hoping maybe there's another password to set, and further parameters
to adjust. Or that one of the parameters I don't see doing anything
can be made to do something, somehow. I don't know -- I'm grasping at
theoretical straws here.

Could somebody with a little (or a lot) more experience than I've got
give me a couple of pointers? Thanks kindly...

[crossposted to sci.electronics.repair and rec.video]