Archive for February 2011

Apple Cinema HD 23inch dies, then resurrects

This morning I was greeted with a blank screen and the power light flashing short-long-short, and groaned at how expensive today was about to get.

The Apple support page states that this flash pattern indicates the wrong power adaptor is being used with the display. I’m using the original 90W adaptor supplied with the screen and keep it powered via an APC UPS.

Fortunately with a bit of googling I found the ‘paper w’ solution here and on the post by jakobeon on the Apple disscusions forum. Essentially by using a strip of paper to blank off the middle of the 5 output pins from the power brick, the display is back to life.

From reading through comments made by others in both forums, and scanning over the power adaptors page, I’m forming the following conclusions. (Note: these are my guesses based only on my interpretation of other’s anecdotal evidence rather than anything authoritative).

1. I suspect the middle pin is used only to allow the monitor to sense which of the 3 Apple power-bricks is attached. If so then it seems more concerned with protecting the monitor from a low power brick, rather than from being overloaded somehow.

2. A number of people have indicated that simply replacing the brick like for like or with the higher power version makes no difference. This suggests to me that the fault is within the electronics of the monitor, when detecting the power source at switch-on, rather than in the brick.

So while this is far from an ideal solution, it is cheap, simple and quick to implement compared with trucking everything back for repair. However if in doubt, get it repaired by Apple – don’t blame me if your house burns down.

Finally using a decent mouse-surface

I’ve been using Apple Magic Mouse for some time. I love it. I’ve used loads of optical mice before it. The one thing that annoys me, even with this mouse, is that it’s accuracy depends very much on finding a decent surface.

I tried loads and loads of surfaces. More or less any surface (except transparent) will do for short stints. But for my workstation, my most used have been the cover of a hard back note-book (such as the Black n’ Red Casebound Hardback A4 Book), glossy magazine covers, other cardboard rectangles (e.g. the back of a note pad) taped to the desk. All of these surfaces tend to suffer the following problems:

  • They wear out
  • They move across the desk unless taped down
  • They are abrasive t the mouse – the tracks on my magic mouse are looking a little worn
  • They get grubby
  • They they turn to mush if coffee is spilled on them
  • Eventually the only relationship of the screen pointer to the mouse is that it moved

Now I think I’ve finally found a surface that will not wear down my mouse rails any further, so far yields extremely accurate results and will stand up to a tea spillage. Unfortunately costs a few quid, but that’s better than trying to accommodate a pointer with a mind of it’s own when on a deadline. The Razer Vespula Gaming Mat.

cPanel and mail subject filtering

If you are using ‘User level filtering’ of email in cPanel (v11.28.83), applied to the Subject header of an email, you may encounter circumstances where sometimes the filter fails for no obvious reason. On investigation of the email headers, it turned out that a certain sender was folding email subject headers over multiple lines. If the phrase being searched for was split over two lines within the header, the filter would fail.

For example, with rule : Subject contains ‘testing 123’

1. this would work:
Subject: line 1 testing 123

2. this would work:
Subject: line 1
 line 2 testing 123

3. this would NOT work:
Subject: line 1 testing
 123 line 2

It turns out that this is because cPanel simply passes the filter information down to exim, and it is here that the behaviour manifests.

I have posted an entry to the feature requests forum of cPanel, for it to be configured to better tolerate multiline subject headers. If you are encountering this problem, it would be helpful if you would contribute to that thread.

In the meantime a workaround is to use the ‘matches regex’ filter, replacing spaces in your match-phrase with ‘\\\\s+’. For example the following rule works in each of the three samples above.

Rule: Subject matches regex testing\\\\s+123