Monday, April 23, 2007

Surge Suppressor Causes Temporary Cursor Freezing

--A Fantastic Tale of Solving the Unsolvable--
If I hadn't witnessed this myself, I wouldn't have believed it. This is a computer diagnostician's horror story.
Some years ago, a friend decided to buy his first personal computer in the World Wide Web era (he had been and continues to be an avid WebTV user). Due in part to my encouragement, he chose to buy a Macintosh. Careful shopping resulted in the purchase of a year-old iMac 333MHz. I accompanied him on the trip to purchase the iMac from a private individual - I performed some rudimentary tests upon the hardware and affirmed the used iMac's fitness.

Not long afterward, the friend reported a problem: the cursor would intermittently freeze. Curiously, he discovered that in an unpredictable period of time (from minutes to hours), user control sometimes eventually returned. The symptoms appeared while he was running a variety of applications. The circumstances under which they appeared had no apparent commonality.
My friend's comment about this previous paragraph: "This caused incredible frustration with the iMac, even causing me to put it away and not touch it for about 3 months when I first tried to learn how to use it. It was my first Mac and after experience with bullet-proof DOS machines, a real disappointment until the problem was discovered."
Some known issues of the time exacerbated our inability to solve his problem. For instance, Apple had identified a problem with slot-loading CD drives which caused system freezing and had released a firmware upgrade for the CD drive. This produced no helpful results.

Many diagnostic experiments were performed attempting to solve this problem:
  • keyboard & mouse replacement
  • RAM replacement
  • formatted drive
  • installed OS 8.5, 8.6, 9.1, 10.2
  • firmware update per Apple
As with all intermittent problems, diagnosis was frustrating. On a couple of occasions, he brought the computer to my home and we would sit and talk while I aimlessly Web-browsed on the suspect machine, waiting for the symptom to appear. It never did. He reported that occasionally he would go a couple of days without symptoms, so nothing was concluded.

A couple of years passed, and this was always nagging at me: the problem I never solved; the friend's Mac that I couldn't fix; the friend's Mac I'd convinced him to buy and approved for his purchase.

Eventually, after formatting the iMac's internal drive and installing OS 10.2, the symptoms persisted. I gave up, assuming that the problem was hardware-related. Perhaps it was USB-circuit related - a motherboard swap as the likely fix.

Instead of replacing the motherboard (a decidedly unprofitable move, in the face of the changing state-of-the-art - and what would have been a disastrously unsuccessful move, given the final outcome), he decided to buy a new computer. I suggested an eMac. After some deliberation, he bought a brand-new eMac 700MHz.

Two weeks later, my phone rang.
Friend: "You'll never guess what's happening with my new eMac."
Me: "No way."
Friend: "Yep."
Me: "Are you using the new keyboard and mouse?"
Friend: "I'm using the keyboard and mouse that came with the new eMac."
We apparently didn't resolve the problem in that call. A few days later, when the friend experienced the problem again, he experimentally removed the surge suppressor from his computer, plugging directly into the wall outlet. He experienced NO further problems.


Not only did he never see the problem again, but he fired up the old iMac and never saw the problem there again either. Re-installing the surge suppressor re-introduced the Temporary Frozen Cursor symptom. After running both machines for weeks with no symptoms, his conscience was clear enough that the iMac was completely fine that he eventually sold it for not much less than he purchased it two or three years earlier.
(NOTE: Surge suppressor model: “Surge2+”, model 30022, UL listed, bought at a Home Depot for about $10, with “$5000 equipment damage guarantee.” I don't recommend it.)
If he hadn't purchased another brand-new computer which was identically vulnerable to whatever characteristic was introduced by the surge suppressor, we'd never have had a solution. I've told this tale within my circle of technically-adept friends, and not one of them would ever have suspected this possibility.

Having said that, I hope never to suspect a surge suppressor again. It's just too strange. I can't believe it's even possible. In all my years as a computer hobbyist and professional (since 1981), I've never seen anything like this. Especially that whatever the mechanism of failure was, it caused a 1999 iMac and a 2002 eMac (which probably have completely unrelated power-supply circuits) to temporarily stop responding to the USB bus, only to completely return to normal functionality in time - without crashing the computer.

I've posted this, not with the expectation that it will actually be the solution to anyone's symptoms (but by all means let me know if you encounter this), but because this was also a painful learning experience. I had been thorough in my diagnostics of his iMac. None of the hardware or software infrastructure which I was able to test on his computer were at fault. But my mind was closed to the possibility that something _past the plug on the AC power cord_ could be suspect. When you're a diagnostician, you tend to adopt a process of elimination. Mistakenly eliminating a part of a system without can lead down a an inappropriate logic path - and I know that. I will frequently review the eliminations I've already made, to check for careless logic errors. And yet, I never even included the AC power source in my mental logic tree.

Monday, April 16, 2007

Send Larger Files with YouSendIt

If you've ever tried sending a friend a file larger than 10MB or so, you may have discovered that your email service prohibits such large file attachments.

A Web service called YouSendIt allows you to send files up to 100MB for no cost by allowing you to upload to their servers, from which your recipients can then download from any Web browser. With the free service, your recipients will be exposed to advertising when they pick up your file. Several tiers of paid service eliminate advertising and raise maximum files sizes (up to 2GB) and monthly data limits (up to 200GB/mo).

Sunday, April 15, 2007

CompUSA Stores Closing List

In February 2007, CompUSA announced that it would close 126 stores - more than half. Sadly, our closest store (Burbank, CA) is one of those stores - it's half-empty now. Not that CompUSA was the greatest store, but the resource was remarkable - to be able to visit their website and tell anyone I know whether an item they needed was reported to be in-stock in a nearby store is fantastic (you can see retail location in-stock estimates with Radio Shack and Best Buy, among others).

Here is CompUSA's list of all the stores which are closing. The closing stores are currently selling merchandise at discounts of 10 to 40 per cent (more of the former) - I've been in two, and they're pretty picked-over at this point.

Monday, April 09, 2007

Apple to Sell Non-DRM Music

In February 2007, Steve Jobs presented a treatise titled "Thoughts on Music" in which he wrote that Apple would be more than willing to sell music without restrictive and invasive Digital Rights Management (DRM) - citing that it was music companies that demanded this technological restriction.

On April 2, Apple announced that it will offer EMI Music's entire digital catalog DRM-free beginning in May. At $1.29, the EMI songs will be somewhat more expensive than the rest of the iTunes Store catalog (typically $0.99 per song), plus the songs will be encoded as 256Kbps AAC files - twice the sampling rate of DRM-encrypted iTunes offerings. EMI and iTunes will allow customers who previously purchased DRM-protected EMI titles to upgrade to DRM-free versions for 30 cents per title.

The non-DRM songs will be playable on any number of devices, as opposed to the Apple's original (but generous) limitations - 5 computers, unlimited iPods and unlimited (personal use only) CDs - though these have somewhat less fidelity than a commercial CD.

Apple and EMI may have really started something. Let's hope the music industry gets it.

Prepare for Hard Drive Failure

Anyone who knows me has heard me say, "Hard drives will fail," and yet we will all be caught out eventually by a hard drive failure. The question is how much you're willing to lose when that failure eventually happens.

Hard drives, or hard disk drives, are the magnetic storage devices in your personal computer that perform long-term storage tasks. That is, anything you'd like to keep after turning the computer off. (Short-term storage is done on memory chips, which are hundreds of times faster and more expensive than hard disks, but which lose all their stored information when the computer is turned off.) All your programs and every piece of data you create and save are stored on this device. The operating system which makes your computer a computer is also stored as information on the hard drive.

But hard drives are mechanical devices, with not only a motor spinning a metal disk at thousands of revolutions per minute whenever the computer is on, but a delicate mechanism which moves a tiny magnetic "head" back and forth across a radius of the disk (remember vinyl record players? rhis is just like a tonearm), oscillating at rates which make the arm appear as a blur. It's one of the only mission-critical mechanical parts in a modern computer, and unfortunately, it's where all our stuff is (to quote George Carlin).

Internet giant Google published a paper in February 2007 to share the results of a study they did on hard drive reliability. They are certainly one of the larger users of hard drives, and the study was based on 100,000 of their drives (which may or may not represent a majority of the drives in their "server farms" - I suspect that information is "classified"). You can download a PDF file of the report here. Somewhat disturbingly, the failure rates they observed (without repsect to manufacturer) exceed 8 per cent in the second year of operation. As a household with (currently) 10 hard drives in daily use (including our TiVos, which run 24/7), that pretty much means we'll lose a hard drive every two years - and we do.

That said, I say again: hard drives will fail. Everything on your computer may go away forever.

Truthfully, you may be able to salvage the data on a hard drive after it fails. If you're lucky, the drive will act strangely enough to alarm you (i.e., the computer doesn't boot), but will work the following attempt. But it might not. There are data recovery services available - companies like Drive Savers who charge hundreds or thousands of dollars to recover data by means as elaborate as you can afford, including clean-room disassembly of hard drives and re-mounting the "platters" (which contain the data) in new drive mechanisms.

So establish a backup plan. If something you do on your computer takes effort (including just having a running computer), then it's worth effort to put the data in another place. Among the possible backup solutions:
  • burn data to CD or DVD
    • multiple copies, and some off-site in case of fire or theft
  • copy data to an external hard drive
    • USB or FireWire connected
  • copy data to an online data service (some free, some paid)
    • i.e., Xdrive, iBackup or Mozy
    • Mac users can use a .Mac account
    • this solution may be inappropriate for large amounts of data, as all data must pass over your Internet connection