There are, however, solutions. First, there’s the semi-official Microsoft solution, which involves some really hairy poking around in the system registry. (And, by “really hairy”, I mean that it looks signficantly more so than poking around in the system registry usually is.)

There’s also a handy little freeware utility that does those changes for you automatically, created by the fellow who runs IntelliAdmin.com. His blog post describing it is here, and the actual download is here. I tried it out, and as far as I can tell it worked perfectly (aside from not actually closing the window when done). He suggests setting your clock ahead to November to watch the time flip over to see if it worked, but it’s easier just to go into the “Time” control panel that you get from right-clicking on the clock and selecting “Adjust Date/Time”, and looking at the “Time Zone” panel to make sure it says “Pacific Daylight Time” (or whatever) rather than “Pacific Standard Time” for the time zone.

For those of you still running Windows 98, he also wrote a fix for that, even though there isn’t an official Microsoft solution at all. The blog post about that one is here, and the download is here.

It’s an interesting observation on advertising, too. It probably took him a day or so to code up this program and test it, and he’s now got a first-page Google hit for people looking for a solution to one of the bigger problems of the month — and people like me are passing around links to his blog, too. You just can’t buy advertising that good.

(The rest of his blog looks fairly interesting, too, if you’re doing Windows administration. This little trick for automatically putting the current date in a filename is particularly neat, for instance.)

One particularly nice feature is that, since all of the GNU/Linux stuff is operating in a single process on the Windows side, it’s easy to set the whole thing to a priority of BelowNormal, and thus even when I’ve got a compilation running and taking up as much CPU as it can hog, it doesn’t slow down anything else I’m doing at all. And it turns out that there’s enough slack in the system that this doesn’t give it any noticable lag in the terminals, even.

The one problem with that is that it completely confuses the software clock on the operating system in the virtual machine, though. When I’ve been using the CPU heavily on the Windows side of things, I’ve seen the GNU/Linux time lose 10 minutes out of 15! VMWare does a nice job of keeping the hardware clock up-to-date, but Debian is set up so that everything depends on the software clock, which only gets synchronized to the hardware clock on bootup. It’s not a critical problem, really, but it’s somewhat annoying to have to remember that a file date of three days ago (or whatever) means “a minute ago”.

The right solution to this is not ntpdate or some other NTP solution. The Windows clock is already synchronized over the network, and the VMWare virtual hardware clock is synchronized to that (I presume), and so there’s no need for adding extra traffic to the network. (Especially since it’s dialup, and disconnected from the internet and any NTP servers half the time.) Nor is the solution something like adjtimex, which tweaks the speed of the software clock; the time skew is a function of Windows-side computer load, and thus quite random, and a static speed tweak is not much of an improvement.

Instead, a better solution is hwclock --hctosys, which synchronizes the software clock to the hardware clock. Because the skew is quite large and needs correction quite often (and because cron is using the skewed software clock for timing, and thus loses time), I added the following to my root crontab:

* * * * * /sbin/hwclock --hctosys


So far, it seems to be working beautifully.

A 1997 Geo Metro is one of the cars with an integrated headlight-and-signal-light unit that’s accessed from the front corner of the engine compartment, so I popped the hood and went to work. The lens is held on by a couple of obvious clips, so I removed those. No luck; obviously there was something else that needed to be unfastened on the bottom, too. The next obvious thing to undo were a couple of large screws holding the entire light unit on. I removed those, and still no luck — there was something holding it on the outside bottom corner, which I couldn’t figure out how to get to.

This, I concluded, was the appropriate time to read the documentation, in the form of the owner’s manual. The owners manual explained that one didn’t actually remove the lens or the housing at all, but replaced the bulbs by reaching in behind the light housing, unfastening the socket, and pulling it out. It went on to say — and this is only a mild paraphrase — “Reaching the socket to unfasten it is actually physically impossible unless you are a leprechaun. You will want to take your car to the dealer and let them do it.” Back to plan A.

Some more investigation found the third screw holding the headlight unit in place, hidden in a cavity behind the bumper that I could either look into or reach into at any given time, but not both. So I removed that while contemplating the pipes running across the ceiling, and pulled out the headlight unit, and pulled the socket out of the now-accessible back of it, and discovered a small light bulb entirely unlike the one that the parts store had sold me to replace it.

A small light bulb which, to all appearances, seemed perfectly intact and functional.

Some further testing of the corresponding lights on the other side of the car informed me that what I had just gone to all of that effort to access was not, in fact, the turn signal light at all, but merely the parking light, which was just as functional as it appeared.

So, thus enlightened, I reassembled the headlight unit with only slightly less effort than had been required to disassemble it, and then replaced the actual turn signal bulb, which is in the middle of the front bumper behind a lens that’s held in place by two quite obvious and quite visible screws that are, as it turns out, entirely trivial to remove and replace.

Some time ago, I posted a comment on This Is Broken, noting my frustration with motherboard-mounted AC power jacks on laptops, and noting that I had fixed a couple of them by following some online directions. Several people asked me to explain further, and I decided it would be useful to write up a more detailed explanation of how I did it.

First, the keywords: My experience is with a Compaq Presario 1210 laptop (which is very similar to the Compaq 1600 series), and a pair of HP Pavilion xf235 laptops, but this should apply to most similar laptops; the advice is mostly generic.

The problem, in short, is that most laptops have their AC power jacks hard-mounted to the motherboard just like any other soldered-on component, and for many of them this is the only structural connection. Unlike most other components, though, power jacks regularly get yanked on when someone steps on the power cord or such, and the solder joints (or the mounting tabs, which after all are pretty thin metal) start to fatigue, and eventually they crack. At this point, the laptop will only charge if the plug is twiddled “just so” (if at all), and doesn’t work reliably.

The official solution, of course, is to replace the motherboard — which fixes the symptom, but not the overall design problem. On a laptop with a street value of $300, this is also not an economical solution. But it does mean that you don’t really have anything to lose if you toast the motherboard trying to fix it yourself.

So. Enough preamble. Here’s how I fixed the problem.

DISCLAIMER: THIS IS A DESCRIPTION OF HOW I DID THIS REPAIR. FOLLOW THESE INSTRUCTIONS AT YOUR OWN RISK, AND USE YOUR OWN JUDGEMENT; I MAKE NO WARRANTY THAT YOU WILL HAVE A WORKING LAPTOP WHEN YOU FINISH. SOME MINOR STEPS HAVE BEEN OMITTED.

On the Compaq, I used the solution that I found on http://www.delanoscientific.com/cpq1675.html. Essentially, you take a three-inch strand of some form of heavy-but-flexible two-conductor wire — that site recommends a good grade of speaker wire, but I happened to have a dead iBook power supply that I salvaged some wire from — and solder a socket on the end of it that matches the plug on the power cord, feed it through the original power jack hole in the case, and solder the other end to the motherboard where the original power jack used to be. One trick is to tie a knot in this new pigtail just inside the case, so that pulling on it only pulls on the knot, rather than pulling on the solder connections.

On the two HP Pavilion computers, I found a better solution. There is a hole in the case, right next to where the power jack goes, that’s intended for a PS/2 keyboard or mouse plug on other versions of the laptop. However, it’s unused and blanked off, which makes it a great place to put a case-mounted power jack — and it turns out that a standard 1/2″-diameter panel-mount jack fits perfectly. I used a Philmore No. 248 “DC Power Jack”, which has 2.5mm x 5.5mm pin and socket diameters, thereby matching the original plug. While you’re at the electronics shop, get a decent soldering iron and a power supply for it that lets you control the temperature. If you haven’t done much soldering before, find some sort of discarded computer-board junk that you can practice on.

Here’s what the new case-mounted jack looks like when it’s installed; the original power jack hole is just to the left of it:

Actually doing the replacement took me about two hours, on the last one I did. The time-consuming part is that you need to completely disassemble the laptop to remove the motherboard. This starts (on the HP Pavilion computers) with gently popping out the panel above the keyboard that has the CD playback and volume controls on it, and continuing by removing every screw you come across. A digital camera is a very useful timesaver here; photograph the screwdriver pointing to every screw you remove, put the screw next to a number on a numbered piece of paper, and photograph it there — then, go through the photos backwards and you have a detailed set of reassembly instructions.

When you have the motherboard all the way out, the next step is to remove the remnants of the old power jack, and solder on some one-inch-long wires (or the pigtail, if you’re not using a case-mounted jack; remember to feed it through the case first!) in its place.

Here, it’s worth noting that the original power jack has three pins, and acts somewhat like a switch. One pin goes to the ground, and becomes connected to the power-adaptor ground when the adaptor is plugged in to the laptop. The second pin is the +19.5V (or whatever the power voltage is) line; when the adaptor is not plugged in, it becomes connected to the ground pin. The third pin is a logic pin for determining when the adaptor is connected; it is open-circuit when the adaptor is not plugged in, and connected to the ground pin when it is. (Unfortunately, I didn’t keep a record of which pin goes with which connection to post here; sorry.)

This could theoretically be problematic with the pigtail-mounted socket, as that socket only has two connections — the logic line for sensing whether the adaptor is connected does not exist. I simply ignored this problem on the Compaq laptop, and the computer seemed to work fine; it may or may not work properly on other computers. On the case-mounted jack, there are three lines, so this is not an issue.

Meanwhile, speaking of the case-mounted jack for the HP Pavilion laptops, there’s the issue of attaching it in the case. Remove the blanking plate from the case by appropriate means (I did this by grinding off the heat-swaged mounting pins), and install the jack in the hole that this leaves. You’ll need to remove a bit of material from the inside top of the jack to prevent interference with the top half of the case later; now is a good time to do that. Also, if you want to be fancy, you can cut a small rectangle out of the blanking plate and superglue it in place to cover the old power-jack hole.

Anyhow, you then reinstall the motherboard (with its new wiring) in the case, and — if using the case-mounted jack — connect the wires to the jack. On the HP Pavilions, make sure the wires aren’t over the LEDS immediately behind it on the motherboard; there are clear-plastic “light pipes” that have to go on top of those, and the wires can easily get in the way. Then reassamble the laptop, and that’s “all there is to it”.

In comments on the original version, someone mentioned that http://www.laptopjacks.com sells exact replacements for the original laptop power jacks, if you want to go that route, though they’re rather more expensive than the generic parts. Other people mentioned repairing the following laptops (which I’ll list for the sake of Google) with this advice: HP Pavillion 1150, Compaq Presario 1685, HP ze1115, HP xt412, HP Pavilion ZE43xx series, Compaq 2195US, and a Compaq 2100. I’m particularly entertained by the fellow from Montana with the Compaq 2100; he couldn’t find the right replacement fitting, and so ended up using a trailer-hitch plug set from the local truck stop.