Indepth analysis of keyboard sturdiness: T4x vs. T6x (Long)

[dr_st]

While there is now almost a consensus that the overall build quality of the T6x series is superior to that of the T4x, one of the things that people, on average, rank higher on a T4x is the way the keyboard feels. Although not everyone agrees, and many discussions have spurred on the difference in feel between different keyboard manufacturers, my personal experience, after 4+ years with a T42 and 2 years during which I played with a few different T60/Z61t/T61 units, leads me to conclude that the difference IS there, and it IS in favor of the T4x.

Prelude:

Most of my experience both on T4x/R5x and T6x/Z6x keyboard has been with NMB. If there are tangible differences due to manufacturer, the experience may be different. However the things I will discuss in this post seem, to me at least, as more fundamental, so I am inclined to believe that this difference will not be big.

Symptoms:

So what is the difference in feel between T4x and T6x? Well, I'd say, that it's mostly how firm the keyboard and each individual key is.

With my T42, each key is 100% firm, and gives excellent feedback. The only way to get any part of the keyboard to flex is to apply strong pressure, which never occurs during normal typing. The keyboard is more rigid than most desktop keyboard, including my favorite Lenovo USB Enhanced keyboard. One of my neighbors has an R50e, and the keyboard feels exactly same - firm, excellent feedback, no flex, quiet.

On the T60, while the typing experience is still excellent, it still does not feel quite the same. The keyboard feels softer, flexes much easier if pressure applied at certain points, individual keys feel more mushy. Overall keyboard sturdiness seems uneven across the board, with the right half feeling as sturdy as the T4x keyboard, and the top left quadrant experiencing the worst flex. I experienced this to varying degrees and with slightly varying symptoms on three different T60s (both 14" and 15"), one Z61t, and all of my colleagues' T61s (although 95+% of my typing experience has been with the T60s).

Before continuing, I must reiterate that overall the typing experience is still excellent. If it wasn't for my perfectionism and experience with the T42, I probably wouldn't even notice it. In fact, it took a long time before I started actually differentiating the feelings. The advantage of the T42 is not big, but it IS there, undeniably.

Symptoms indepth:

In addition to the feeling that the left side of the keyboard is less rigid, I also noticed that some keys are louder, emitting a hollow or a doubled sound when pressed. A brief investigation showed that the reason is that the keyboard support under these keys is simply insufficient, and so it does not sit flat, and there is a gap of air between the keyboard and the chassis, which causes the entire keyboard to depress and hit the chassis when a key in the area is pressed, producing the hollow sound. This symptom is exhibited by several keys: F3/F4, 3, 4, E, and a few others. If I press and hold down the plastic frame around the Thinkvantage and sound buttons, the keys become much firmer and quieter.

This also explains why the problem is mostly experienced on the left side. On the right side, the rollcage and optical drive provide firm support to the keyboard, which is missing on the left side, where the keyboard lies directly on top of the fan and other components.

One would think that this problem can be solved by adjusting and reseating the keyboard and palmrest. However, experience shows that this is not as simple as it sounds. I tried it multiple times with multiple machines, and while sometimes I could get better results, I could not achieve a 100% firm keyboard. Granted, I may not be as handy as some (although the IBM repairmen that fiddled with the chassis a few times did not overall do a better job than me), but I must say, that I disassembled and reassembled the keyboard on the T42/R50e a couple times, and not once experienced any sturdiness issues. The keyboard always sits firm.

Now, the keyboard backplate itself is no less rigid on the T4x than on the T6x (unlike the new T400/T500 keyboards), so what is the likely cause to this behavior? Continue onto the next section to find out.

Root Cause:

I believe that the answer is simply due to the differences in how the keyboard is held down on T4x/R5x compared to the 60-series models. In the old Thinkpads, the keyboard is screwed in by 3 or 4 screws (depending on 14" or 15"). Tightening the screws makes the keyboard firmly attached to the chassis in several spots, eliminating gaps and flex.

On the 60-series, there is only one screw, right in the middle of the keyboard. This cannot hold the keyboard down well enough. Instead, the construction relies on the palmrest holding the keyboard down. The palmrest is fixed by 4 screws, distributed almost evenly across the width of the laptop. In theory this may sound good, but on practice, while the bottom part of the keyboard is held down quite well, the top part still has too much freedom, which is why the worst issues of flex are experienced in that top left area, which is poorly supported by the chassis and isn't held down strongly enough by the palmrest.

Playing with the palmrest and keyboard screws, tightening and loosing them until a good balance is achieved, can help somewhat. However, it is problematic, because there are too many degrees of freedom in the construction. Moreover, the screws and screwposts do tend to wear out more and more each time you mess with them, and there is a risk of ending with something completely loose one of these days (not to mention that the palmrest itself is fairly fragile around the corners and can break when attached/removed).

So the situation leaves me a bit disappointed with the keyboard sturdiness on the T6x (and compatible) series, and looks like most of the problems are due to design.

Why was it changed from the successful implementation of the T4x series? I don't know. The idea of reducing the number of screws does not hold, since you have to remove all palmrest screws and the palmrest itself to access the keyboard now. Maybe the idea was to reduce the number of screws in the keyboard, to make more paths for the liquid drainage holes, I don't know. Whatever the reason was, it just didn't work. Not 100%.

Side note:

Incidentally, it seems like the 4 palmrest screws on the T60 are not even sufficient so completely securely hold the palmrest down. There is some flex and lack of flatness in the area directly under the left arrow key (where the palmrest has a corner), especially on 15" models. I feel that a fifth screw post there would be a good idea, but Lenovo engineers probably wanted to reduce the number of screws to the minimum possible that will still keep the construction solid enough, so they didn't put it. And it's not like the flex there is anything detrimental to the overall sturdiness of the construction. It is just a (very minor) cosmetic issue.

[idxman01]

Well dr_st, I was just fine with my T60p until you and your thorough post made me sit here for 10 minutes and poke at the keyboard. I'm not sure if it's the power of suggestion, but it certainly seems like that left-hand side is very hollow and doesn't provide the same solid snap as the right.

Along with the top-left as you mentioned, my C and V seem particularly hollow and mushy.

I haven't taken the kb off, but are there any opportunities to insert some padding or insulation without disrupting any necessary airflow?

[Zender]

Just one little remark. I noticed that my top left corner (T60 14") started to have much better feel / less flex after installing second WWAN (AUX) antenna, which goes exactly to the top left corner.

[ZaZ]

I'd add in my 14" R60 was absolutely fabulous. It's probably the best notebook keyboard I've had. It was the NMB keyboard. I had a T41 and T42. It was firm everywhere. Key pitch was perfect. My 15" R60 is a little different. I believe it's the ALPS keyboard. There's a little more give to it, particularly around the G, T, and 5 keys. Also the UltraNav buttons seem more noisy. They don't have the smooth action like other ThinkPad keyboards I've used while the regular touchpad buttons seem fine. I don't if it's the 15" design is different or the ALPS keyboard is different. Both feel like solid notebooks. It's not really worth the extra $$$ to me to buy a NMB keyboard to test it out.

[agarza]

Yes, it's sad to know the T6x series keyboard is not as sturdy as the T4x ones. I happen to buy a used NMB for my T42 to years ago.. The kb felt really great compared to the stock kb it had.
I wonder how the NMB keyboard on the T6x compares to the T4x and even to the T61 Chicony and ALPS kb.
I miss my T42p, I'm not really picky about Thinkpads features, such as lousy screens but having a 'cheap' keyboard feel on my T61 does not make me rejoice claiming I have the best laptop keyboard. I'm just wondering if engineers are stupid or what (I'm one too), by removing those 3 extra screws in order to secure the kb firmly to the chassis.

My 4:3 T61 flexes considerably just above the volume keys it feels not a tank anymore. I might try in the future modding it to make it sturdier.

[dsvochak]

I’ve got a T41 and a T61 with NMB keyboards. I’m one of those who think the T61 “typing experience” is better than that of the T41. Apparently not everyone has the symptoms described or notices the symptoms.

My T61 keyboard “typing experience” is closer to the typing experience of an IBM Selectric than the T41. That’s a better typing experience to me.

[dr_st]

My 4:3 T61 flexes considerably just above the volume keys it feels not a tank anymore.

Same here (T60 4:3 14"). The 15" is somewhat better, but still has some flex. On the other hand the keyboard seems to sit better on the 14".

Reason for the flex you described seems to be the same as to all the things I mentioned: lack of proper support under that area. Granted, Lenovo engineers probably believed that it is not needed there, and they are probably right. It won't affect the durability of the laptop. But to me (and not only) the way things feel is also somewhat important, while in these design changes it seems that they clearly went for "function over form/feel".

I’ve got a T41 and a T61 with NMB keyboards. I’m one of those who think the T61 “typing experience” is better than that of the T41. Apparently not everyone has the symptoms described or notices the symptoms.

My T61 keyboard “typing experience” is closer to the typing experience of an IBM Selectric than the T41. That’s a better typing experience to me.

You make a good point, but I'd like to split it into two.

My experience with a relatively large number of T4x/R5x compared to T6x models suggests that the symptoms described (sturdiness vs. mushiness) are ubiquitous. At least I have not seen a single counter example in the couple doznes machines I got to briefly or extensively touch. The only way I can believe something like this would happen is if the T4x keyboard or bezel really were somehow improperly assembled.

However, what makes typing experience better, is largely personal preference. For instance, my Lenovo desktop keyboard is not as rigid as my T4x, but does it mean that I prefer the T4x? Not necessarily. Similarly, I don't have a problem with the T60 typing experience, except when the "hollow key" syndrome is particularly noticeable, and that really varies from unit to unit.

[dr_st]

Another very long post coming, with a peculiar solution, for those who are interested in a little modding.

After this indepth analysis I became gradually more and more bothered with this mushiness and lack of support in my T60 15" keyboard, in the area of F4/F5/3/4 keys. On my 14" T60 this was present, but to a far less extent, not noticeable during normal work.

I decided to do an indepth analysis. Of course, the first thing I tried was swapping the keyboards between the machine, to determine whether the problem is the keyboard or the chassis. Turns out it is the chassis - the chassis on mt 15" unit apparently just doesn't have enough support in that area. I couldn't figure out why, since all the parts of the chassis and the board (which support the keyboard) look the same. Maybe it is just imperfect assembly of this particular unit I have.

I was looking for something to give more support to the keyboard, just in that area, and came up with the following: I found a small thin piece of a rubber magnet, with just a bit of glue on one side, cut out about a 0.5cm by 2cm piece, and glued it to the back of the keyboard in that precise area where support for the backplate was lacking. The tiny bit of glue that was the rubbery magnet was enough to make it hold, but not difficult to remove should I want to.

The situation dramatically improved. The keys in that area no longer feel mushy and there is no hollowness when I press them. It's not 100% gone, but it is on par with my 14" T60 now, which is far better than I had before.

Just a little idea for anyone experiencing similar issues.

[dr_st]

After a while, I realized that the original modding described above was still not enough.


The mushiness in the left-middle area went away, but the entire left column (Esc down to Fn keys) still lacked support. You could actually see and feel the entire keyboard flexing up and down in that area and the keys made annoying dual sounds when pressed.

The issue was fixed by attaching two more similar pieces of the rubber magnet in strategic places under the keyboard - one under the Esc/F1, one between the Tab/Capslock/Q/A keys.

And now it feels really perfect. Better than the 14" T60. Almost, but not quite as good as the T4x.

My gut feeling is that the underlying problem is that the chassis is somehow warped or not screwed tight enough somewhere, which causes this lack of support. But if you, like me, happen to be one of the unlucky ones with this problem, the mod described here is far simpler than messing with the chassis and hoping you can somehow fix it (in all honesty, I wouldn't even know where to begin).

As much as I adore the engineering and design of the T60, the keyboard support is one area where they clearly didn't do it right.

[epr02]

I just purchased a t61u 15" and looked up the keyboard = chicony. After reading through this thread I can say there is absolutely zero flex anywhere on this keyboard! It is rock solid everywhere. Mfc date May 2009. This keyboard is the absolute best I've ever had. I've been using thinkpads since 1998.

[MaxRoy77]

Does anyone tried to have support or made warranty request about this ? Replacing the frame, or something else ?

I have a lot of flex over the DVD drive, under the fingerprint reader and the F1/# keys.

Let me know,

Thanks

Max

[MaxRoy77]

I put a credit card under the keyboard, bottom right (covering the arrows keys and the [enter] key), screw it all up and test the keyboard, BAM! flex all gone. So tomorrow like the mod recommended above in that thread I will buy some 2mm rubber magnet and place it on the frame where it lack supports:

- On the frame over the DVD drive/Ultrabay
- Between the heatsink and the left keyboard bezel (speaker) left of the [CAPS LOCK] key all the way up to the [ESC] key

Thanks guys for the tips.

I will keep you posted of the result, if not, feel free to PM me .

[Worzyl]

Yes. Let us know.

[MaxRoy77]

Done.

Keyboard flex mostly all gone.

URL of the MOD pictures with details and exact places I applied the magnetic rubber tape.
http://picasaweb.google.com/MaximeRoy77 ... directlink

The most annoying keys flex is gone: [ENTER], right [CTRL], Arrows and [SHIFT]. Now I love the stiff and metallic souding keys of my Chicony keyboard (sorry I can't type on an ALPS)

The flex that still exist, and that exist on most of ThinkPad is the one where the [ESC], [F1], [F2] over the heatsink fan, there is not a lof of framing there. If someone has an idea , please share.

The palm rest flex is less annoying but still exists, I need to call Lenovo support to have them send a new palm rest since there is a problem with one of the silver sticker under below the fingerprint reader. This might prevent the light clicking when I push hard enough. Then I will try to add some magnetic rubber to limit the gap between the frame and the palm rest. I'll post update when done.

[Worzyl]

Those pictures are excellent! Well done on the mod. I'll have to save those to my desktop...

[Muse]

So tomorrow like the mod recommended above in that thread I will buy some 2mm rubber magnet and place it on the frame where it lack supports

So, I'm curious about this magnetic rubber tape. I take it that it's rubberized tape, 2mm thick and has magnetic properties such that it isn't sticky except to a surface that attracts magnets (i.e. most steel). Is this correct? I assume you can find this on ebay.

Edit: I'm having a hard time finding this stuff on ebay.

[MaxRoy77]

^ Bought it at Rona (Canadian hardware store), HomeDepot, Home Hardware stuff like that.

[dr_st]

Great pictures!

I see you chose to add the rubber to the frame, I opted to stick it to the back of the keyboard, since in my case most of the flex was on the left side, where the frame is less defined and it was hard to find good places to catch the rubber on.

[MaxRoy77]

^ Yes, I have chosen to tape the frame since I don't want to start again when I will change my keyboard

I still don't understand WHY Lenovo kept the frame open with 3 cutouts over the DVD drive as seen below:



I will never be able to fix 100% of the spring of this area. It is a major frame weakness .

[corvette]

Maybe it's a noob question, but: can the 2 mm magnetic tape harm the HDD or hardware in any way? The strength is minimal though.

[MaxRoy77]

No chance if it's not directly on them, I put the tape on the frame.

[TOMSrolla]

Any new update on where to place the rubberized magnetic strip on the ESC ,F1 and F2 area ?

[MaxRoy77]

No

I guess we needs to live with this one.

[dr_st]

Just put it on the keyboard backplate itself, like I did.

[hellosailor]

If you can't find magnet tape or are worried about the magnetism...

Other folks have used the white "foam" rubber double-sided mounting tape, available in stationery and hardware stores. Or there's butyl tape, or silicone tape, both sold in hardware stores with no adhesive on them, used to wrap pipes for repairs and wrap electrics for insulation. These are sold as "self-vulcanizing" tape, it sticks only to itself.

Cheapest simplest thing may be to just buy one cheap plastic placemat at a dollar store, and cut a strip off. Or, a strip from a blown inner tube, bicycle or truck, both free from the back room of repair shops.

[techweenie]

I think some of the flex on the left side on 15.4" models might be related to how well the heatsink is seated over the GPU, and whether or not there is any curvature in the keyboard. I have a T61p which I don't recall having any flex when I first got it, but I have since modified the heatsink to fit the GPU better and now it has severe "double tap" on the left side. My theory is that it no longer makes contact with the rubberized pad on top of the heatsink. I've also seen some keyboards with a natural downward curve to them from top to bottom which, in theory, would help make a tighter fit.