I just tested an old W530 Thinkpad laptop with a B156HTN01.1 LCD panel, which is supposed to be identical or better in every spec to my other old T520 Thinkpad's B156HW01 V4 panel. However, compared to the v4 at max brightness, the N01.1 is a bit dimmer, a tiny bit blurrier (hard to pin down or describe, but very annoying over time), and you can easily see the pixel grid from a distance (on the v4 you have to look close and concentrate to see the pixels at any brightness).
I am curious as to what would cause a panel to fail in this way. My guess would be the backlight, which is only rated to 10K hours, but I would think that would only explain the dimness and possibly the pixel grid. What could explain the very slight blurriness or fuzziness?
Notes:
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I am pretty sure the issues are not related to software drivers or calibration. I used a color calibrator, and I tested using 3 different OS's. Resolution is correct at 1920×1080, and I tried various DPI and anti-aliasing/ sub-pixel smoothing settings.
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The blurriness is slight enough that I keep thinking "it is my imagination", except that I am constantly "re-imagining" that it is causing me eye strain. Perhaps it is the more pronounced pixel grid or a dullness of certain of the component lights relative to others? How can I find out more?
Test 1 – I switched the panels on the two laptops.
- The N01.1 still has a more visible grid, but it is now almost (but not quite) as bright as the v4 and maybe a bit sharper than before. The v4 seems not quite as sharp now. But that may be my imagination.
- The system clock is off at bootup on the W530 (which now has the v4). Could that have something to do with it?
Test 2 – I ordered a new N01.1 LCD panel and another used W530. When those arrived, I compared the faulty panel to the brand new N01.1 panel on the different W530 laptop, and there is not much difference in sharpness. My conclusions:
- The display connector must have been loose before I switched the panels, and that caused some blurriness and/or dimness.
- The N01.1 panel is not as good (to my eyes?) as the v4, despite what the specs say.
Best Answer
Your conclusions are interesting. If I ignore your imagination caveat, one (perhaps too obvious) cause would be some kind of aftermarket filter/protector applied to the screen. I've seen this before, and it was quite difficult to see the filter unless you get right to the edge, particularly if it was applied professionally. It wouldn't surprise me on a thinkpad.