Awhile back I acquired the bottom case, frame, and planar of a T420. It had an i5-2520m in it and hooked up to a monitor I confirmed it working. I plugged in a keyboard, T410 LCD and a TV and had myself a home theater T420 halftop. The cyan tint problem was just the analog video being dumb. The T410 from the same bundle has gotten an i5-540m. Both have been lovely machines to keep around.
Two weeks ago I bought an affordable parts T420, missing CPU and keyboard, to rob the palmrest, lid, and covers for my T420 halftop. Now I have a T420 laptop.
The screen is the LG 1600x900 considered superior to the AUO that my T420s had, although I don't have the T420s anymore to compare. In my opinion the AUO screens are more prone to developing defects and QC problems so I'm happier with the LG. My first AUO (WXGA in an R500) had lots of stuck pixels, my next AUO (WXGA+ T410) had uneven colored backlighting, and last (HD+, T420s) had a lightning bug in it. Only two LG WSXGA+ screens have bothered me so far. Back to the LG HD+, horizontal angles are great and vertical angles are nonexistant. Also the hinges feel stiffer at the extremes. !! I'll live.
The laptop only has a few aesthetic defects, lettering and sticky residue on the lid, missing Lenovo badge, and cracked plastic at the USB ports. I have two perfect T420 bottom cases I could transplant the innards into, I will do that if I upgrade the CPU to an i7 quad core, otherwise there's no need to mess with a well running machine.
Compared with T410 (i5 540m, WXGA)
With the transition to 16:9 aspect ratio LCDs the T420 is wider but shorter than the T410 it succeeds. However the LCD has shrunk more than the laptop, so the T420 may seem oversized for a 14" laptop. The T410 with its "thinner" bezels and 16:10 lcd comes across as elegant. While the T410 has both modem and 1394, the T420 only accommodates one or the other in a replaceable daughter card.
Despite fitted with the 12.5mm Ultrabay Enhanced, the T420's bottom case is somehow the same height as the T410. The T420 is slightly thinner thanks to thinner LCD screens. So they are both oversized laptops, but not as oversized as the 15.6" T510-W530. Both T420 and T410 are wider than 15" 4:3 laptops. Oversized, I tell you!
The LG and AUO T420/T420s HD+ screens seem more vibrant compared to the T410's LG WXGA or WXGA+ screens. The HD+ panels are more evenly lit while the T410 screens are darker at the edges, but the t410's LGs are fairly pleasant to look at. Samsungs are bleh and AUO can be bad. Horizontal angles are better on the HD+ than T410 offerings. The vertical angles are nonexistent on all of them.
The T420 estimates better battery life than the T410 on the same new-old-stock 70++ Sanyo 9 cell I've acquired. The T420 estimates 7-10 hours (probably not true) while the T410 says 5-6 hours fully charged in Maximum Lifespan mode (85wh). They're both high estimates and unlikely to be true. My T500 only estimates 4 hours nowadays with its high-energy CCFL WUXGA and occupied Mini PCI slots, and the X-series in my arsenal need new batteries, so with an SSD this T420 may be my new travel computer!
The laptops are both running spinner drives currently but I've tested them with SSDs and they are blazing fast with them. T420's 2.5" bay is Sata 3 while T410's is Sata 2. The T420 can run an Msata SSD in the WWAN slot @ Sata 2. Both the T420 and T410 are more versatile than their slim counterparts, as the slim models are gimped in battery options and ports, missing SD readers and whatnot. T410s has headache inducing & oftentimes defective Toshiba screens and bad fans. T420s hasn't these problems but still lacks ports compared to normal T420, it also overheats under turbo boost. Only nice thing about the slim T-series is that both their RAM slots are accessible under the laptop, as they are built like the X-series, just oversized and heavier. They're not true T-series in my opinion, they're not even that thin and the X-series will always beat them in lightness.
What annoys me most about the post-CS09 Thinkpads is the plastic bezels appearing popped out for no reason, so I push them back in and that's it, except sometimes the plastic retention clips get worn or bent and the bezels stay out of place forever. The laptops are otherwise solid. I've developed a fondness for the T410 design, it gets bonus points for 16:10 that the T420 cannot match. The T420 has quad core options and 1600x900 in its favor, however. I really want a quad core laptop, but 1600x900 is a major turn off. My perfect Thinkpad is not in the 14" sector, but 15.4".
T500 with quad core and LED WUXGA would be my perfect Thinkpad. At least the latter is accomplished, but how have people modded Core 2 Quad into T61 and not the superior T500 with DDR3 so fast so modern
??? Yes I am biased to my laptop.
Thanks for reading.