Diagnosing R61 screen problems, possibly upgrading?

[CosmicSoda]

I've got two problems with my R61 (CTO-7733): the lights on the inverter board besides Wi-Fi are not working, and the screen backlight is not working.

The inverter board lights started dying a year or so ago with a couple lights going out, then more and more every couple months or so. I figured "old computer, not really worth looking into". Recently, the backlight started flickering when I turned on the laptop and after a few days it stopped working altogether. I checked a few topics with similar problems and narrowed it down to the inverter board, the CCFL inside the screen, or the LCD cable. I replaced the inverter board first and nothing changed; lights still dead besides Wi-Fi, and the screen is dark. I pulled out the board and let the laptop sit for about a week without one (using an external monitor in the meantime). The other day I popped the old board back in to see what would happen and the screen lit up for about 10 minutes before flickering and dying. At the same time I heard a squealing noise coming from the screen and the bottom corners were getting hot.

At this point I'm pretty sure it's the CCFL going back and I'll need to replace the screen, but I want to make sure my reasoning is sound before I drop the money on a new one. That also wouldn't fix the inverter board lights. Could that be the LCD cable, or maybe a blown fuse somewhere?

As an aside, I'm debating upgrading to a new laptop, but I want something with a 16x10 screen and the nub mouse. The T410 was the last of that series with a 16x10 screen, but are there any other models I can look out for? And since it's out of production, what are my best options for finding one (even used)? Alternatively, what are my upgrade options for keeping the R61 up and running for a few more years (it's already got a new battery and upgraded to 2GB RAM)?