Why the need for a second sample? T1 suffered from a pretty glaring problem in my opinion. In certain scenes, parts of the local dimming LED backlight would flash intermittently and at random. Here's how I put it in my original draft of the review:
The Toshiba had a propensity to interrupt dark areas with brief flashes of brightness that were confined to small zones on the screen. The instance we noticed first was during the demonstration sequence from "Digital Video Essentials: HD Basics" (around the 2:50 mark).
When the computer-generated plants fade in from black, flashes appeared in the lower left and upper left of the black background as the overall brightness of the scene increased. When watching "Austin Stevens, Snakemaster" on Discovery HD Theater, we saw brighter flashes, akin to blooming, in the darkness around Austin's head as he leaned toward the light in a cave.
During "Watchmen" the flashes also appeared occasionally and for no reason we could discern. In the initial fight, for example, the lower-left corner flashed briefly just as the Comedian's blood drips down onto the smiley-face pin. A zoom in to President Nixon created another flash in the lower right. Our guess is that LED elements were lighting when they're not supposed to.
When we talked to Toshiba about what we saw, the company insisted on sending T2, which didn't suffer from the flashing issue. We mentioned the problem with T1 in the review, telling readers we'd update the situation when we knew more.
Now we do. Toshiba's reps identified the problem as a firmware issue. Since T1 was a production model (with a manufacturing date of July), chances are some early owners of SV670U series HDTVs might be seeing the same kinds of flashes I did. To address this potential problem, Toshiba has made a firmware update available.
As the company's rep put it: "Based on our current consumer and reviewer feedback, this has not been an issue. However, in our ongoing effort to provide the best possible product, we will provide the update for units with the original firmware."
I tested the new firmware by updating T1, and the upgrade works as advertised, removing the flashes and restoring picture quality to the same level I saw on T2. If you're an early owner of a Toshiba SV670U series, you might want to do the same thing.
Toshiba doesn't have an online firmware upgrade feature like Samsung and Sony, however. Unfortunately you have to call the company's customer service department (800-631-3811) and request to be sent the upgrade; just ask for the latest firmware for your TV. It will arrive on a USB stick, and when you follow the instructions--which took about two minutes in our experience--your SV670U will have the update. And no flashes.