Sporadic missing letters while typing: Not just MacBook Pros; watch for trackpad interference
We previously reported that Apple has apparently acknowledged an issue with some MacBook Pros where the first typed letter in a new text field is sometimes missing. For instance, when filling out a Web-based form, typing the word "dog" in an address field may result in only "og" being typed.
It now seems that this issue affects models other than MacBook Pros.
John Bastin writes:
"I've had this problem for some time on my PowerBook G4. It would seem to happen most often when a new window opens on the Desktop with a text field for entry (like a login window, for instance). Very frequently, when I type the login, the first letter doesn't appear."
Another reader writes:
"Happens on my 4 month old MacBook as well."
Finally, Bill Law writes:
"I have a 1.5GHz G4 powerbook. The missing first letter syndrome has been an intermittent problem ever since i have had the computer (1.5 years). I have never found a reason. It occurs infrequently but regularly (every couple of months) lasts a few days and then goes away. It is infuriating when it is there, but i usually forget about it when it leaves."
Trackpad interference We've also discovered that, in at least some cases, the cause for this issue appears to be accidental trackpad input or interference. For one MacFixIt reader, the problem was a third-paty trackpad protector that was inadvertently generating input on the trackpad, causing letters to skip.
Byron Young writes:
"I removed the Shieldzone track-pad protector (and) everything was fixed. The plastic protector had caused all of the problems. I had caused all of the grief I went through with that little 2x3 sheet of plastic. I really like the protection of the plastic on the case but on the track-pad it broke my computer."
As such, you should make sure there is no physical trackpad obstruction. You might also want to try toggling the 'ignore accidental trackpad input' in the Keyboard and Mouse pane of System Preferences.
Feedback? Late-breakers@macfixit.com.
Resources
It's something else (?) which causes the problem to come and go at will on my laptop.
Jerry
omg! I thought it was my keyboard or my typing but it seems I am not the only one. I just happened to see this article when I was visiting the site! I have to look into this further. I have 2.4 MBP which was bought in July.
I have just sent my MBP in for the second time. The first time I sent it in the missing letters were not just the first ones but scattered throughout the words and also readily apparent in the double letters. I installed the keyboard patch as suggested, toggled the repeat rates, accidental input, and everything and it still does it but not nearly as bad but it is still unacceptable. It is in for the second time and I hope this fixes it but I am doubtful that it will. I assume it is hardware related as it does not do it with a USB keyboard or with a bluetooth keyboard. Oh, I have also made new user profiles and will try reformatting the HD after I try the font cache clearing when it gets back Tuesday. Funny, I switched to mac after using pc's since 1988 when I had the chance to use an Ibook. Bought the MBP since I loved the OS so much... now I am wondering if Mac quality is all it is hyped up to be. I would like to be shown that it is but I am not very happy to date. Cheers and I hope this fix does the trick...
I have also had similar "first letter" problems with my MBP. I think the problem is software because it has occured also when using Apple Wireless Keyboard (not the new MB-like model).
It's likely hardware related. I remember there were missing first letters on my PB G4/1.67 until the PB needed a fix last summer (unrelated to this problem) on AppleCare warranty. For some reason - although it wasn't even a part of the problem - the service provider decided to replace the keyboard and the trackpad as well. For most parts the missing first letter issue has disappeared.
I've been tracking this problem for over two years on various Mac models - not just laptops. It appears to be related to Operating System paging management briefly turning off/losing keyboard interrupts. Most often seen when switching between windows using a mouse click into a text box and immediately trying to type. It occurs as frequently when switching between windows in the same application as when switching to a window in a previously non-frontmost application. It occurs more frequently when the switch results in disk activity. I've observed as many as 3 characters being eaten by this phenomenon (but usually only 1).
I hope Apple does manage to get this fixed but I believe it to be a fundamental OS issue rather than UI based.
I have noticed this problem on a 24in iMac C2D with wireless keyboard and mouse, and attributed it to my bad index and middle fingers. I think your diagnosis is correct -- let's see if this reoccurs under 10.5.
I'm sure that this is probably a one-off keyboard problem,but now that I've read this post, I wonder.
I have a new aluminum keyboard with a new iMac 24". I have used many keyboards before, including my MacBook's, which is similar.
I find that I'm constantly having to correct errors as I type, typically missedspaces that occur randomlywhen I'm typing. You get the picture.
I can type a letter and space alternately, and sometimes the space won't register. I haven't pegged it down to a particular location of pressing on the spacebar. It's so intermittent that I acknowledge that it might just be me not pressing the key fully...but again, I've never had this problem with any other keyboard, and some of the recent reports that MacBook Pro users were having drops of the first letter typed into a text field made me reconsider if it was just my clumsy fingers.
I love the new hardware, but I'm tempted to just use my old iMac keyboard in its place.
Anyone else experiencing this?
AlenShapiro1 has found one possible major cause for this problem, but it's just one of many. Thanks for posting that, Alen--it would be interesting to see if some Macs with this problem would do better after they've been restarted, and so haven't had their RAM loaded up to the point of requiring a lot of virtual memory page swaps. You can see how much paging is occurring, beyond normal paging with OS X's single default swapfile, by looking in the folder at /private/var/vm (use the Finder's "Go: Go to Folder" command)--if there's more than one swapfile there, then you may need more RAM. If your RAM is max'd out, then close all unneeded windows and apps (especially "busy" web browser windows doing some kind of pointless animation that hogs processor time), and see if that helps.
The problem is reoccurring again now in 2007 as of a few weeks ago (sometime end of September) and I will now report this to Apple. I did not report it in 2006 since this machine had gone back 2x to Apple to replace a failed hard drive not long after purchase from Apple and was returned with a damaged surface to the keyboards. I could not afford another return timewise so I let it drop. (10-22-2007)
- by August 24, 2010 11:11 PM PDT
- http://tutplus.blogspot.com/2010/08/type-without-touchpad-interference.html
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