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Archive for February, 2012

Apple Notebook Battery Monitoring

Friday, February 3rd, 2012

While the portability of laptops is the main reason they’ve grown increasingly popular, that portability comes a price, namely rechargeable batteries. Not only do these batteries limit how long you can use the computer away from a power outlet, they gradually lose their ability to hold a charge.

Battery Health Monitor: Another freeware option, not quite as pretty as CoconutBattery, but gives you most of the same information. Battery Health Monitor has a grid at the top that shows you the power status of the laptop. When plugged in, the word “A/C Power” is bold for example; when on battery power, the word is grayed out.

Other indicators include “Battery Depleted” and “Not Chargeable,” neither of which you’ll want to see bolded. Battery Health Monitor also tells you how many charge cycles the battery has gone through as well as the current voltage the battery is delivering.

SlimBatteryMonitor: This piece of freeware is essentially a fancy replacement for Apple’s laptop battery icon.

While it does not provide any of the supplemental data the other options do, SlimBatteryMonitor’s main attraction is that it takes up less space in the menu bar than Apple’s built-in version and is much more customizable, particularly in the colors you can choose for the battery icon…

CoconutBattery: Perhaps the most elegant of the freeware options, CoconutBattery offers a single gray window with three panes and lime green indicator bars. One pane shows the current battery charge and another current battery capacity, indicating how much of your original capacity your battery has lost since you’ve owned it.

A bottom pane of “Additional Info” shows you “battery load cycles” and the age of your Mac laptop in months. CoconutBattery even has a Dashboard Widget available…

Tags: battery
Posted in Cell phone batteries | 1 Comment »

Replacing Laptop Keyboard Key – How To Reattach Laptop Keys

Friday, February 3rd, 2012

The first time I had to replace a laptop key, it took me several hours. I struggled and struggled with the thing, trying to get the clip ends back into the little holder on the laptop keyboard membrane, using tweezers and jewelers tools. When the clip fell apart, I thought I was doomed. I put it back together and went right on trying to install the whole thing in one shot. I think I imagined that laptop keyboards were put together by extremely talented people with very small fingers, which may be the case, but it sure isn’t required. The picture to the right shows the standard arrangement of the four retention points on the keyboard. They can vary a little, some require more snapping in than sliding in.
	The picture to the left shows your basic detached key with the assembled retaining clip still attached. I removed it from the keyboard for the sake of doing this illustration by prying up the top of the key a little and pushing the clip at the top inwards towards the center of the key on one side. Once one side is free, pulling towards that side releases the opposite side, and then the whole key can be slid down, towards the space bar, which releases it from the two little brackets that are closer together. Assuming you aren’t pulling your keyboard apart for fun, you may be starting with half the clip still attached to the keyboard (as below) with all the clip attached to the key, as to the left, or with all of clip mechanism attached to the keyboard, though that’s pretty rare.
So the first trick is to realize that it’s nearly impossible to reinstall the key with the whole clip attached to it, because the larger half of the clip needs to be squeezed in to get under the holders. The retention holders at the top are essentially a closed “U” shape. It’s much easier to take two halves of the clip apart (they are simply snapped together) and install the larger piece that pivots at the top first. I’m showing that to the right, and you can do it with your fingers instead of a screwdriver, but I used the screwdriver so you can see something other than fingers. The next step (below) is to slide the smaller clip, with one end attached to the key, into the bottom two retention points. If you choose to do this without the key attached, or if it came apart on you, make sure the concave part of the smaller clip is facing down. It doesn’t take any force or squeezing, just place it inside the larger clip near the bottom and slid it towards the top. Once that’s done, you reassemble the two halves of the clip by just pressing the little pivot points into place, as at the lower right.

	Now the whole mechanism is assembled and clipped to the keyboard and the top half of the key, shown to the left. All that’s left is to attach the bottom half of the key, which you do by just pressing on the key, shown below to the left. To review, the really critical part of the process is to detach the larger half of the clip from the key and install that on the keyboard first. After that, the smaller clip only goes with the concave part down and the beefier plastic end attaching to the top of the key, or pointed towards the top of the keyboard if the key isn’t attached. The fastest way to do the job is to install the two clip halves without the key attached and then just press the key onto them, starting it at the top since it’s a form of open retainer, and then the bottom just stretches into place when you push down. Whole thing takes a few seconds when you’re in practice and doesn’t even require a screwdriver.
There aren’t any problems easier to troubleshoot than a laptop key the cat has clawed off the keyboard, but what can you do if the cat pulled the laptop off the table and now it doesn’t work? The Lapop Repair Workbook is focused on troubleshooting laptop hardware problems so you can decide whether you want to repair your laptop, pay for a repair, or just buy a new one. It starts with an introduction to all the laptop technologies, follows up with basic troubleshooting and cost trade-offs, and finishes with over a hundred pages of diagnostic flowcharts and text explanations. You can purchase the 191 page printable eBook for instant download anywhere in the world for less than what you spend a week on kitty food.

Tags: keyboard
Posted in keyboard | 1 Comment »

Laptop Power Adapter and Supply – Illustrated how to repair laptop power cords

Friday, February 3rd, 2012

	One day your laptop may refuse to power on even though the AC adapter is plugged in. You’ve probably noticed that your laptop features an LED that lights up when live power is attached and the battery is charging, usually on the front of the laptop body. Older power adapters may also have a status LED to show they are functioning. The AC adapter may have failed if it’s plugged into a good power outlet and the cable ends are securely seated in both the adapter and the laptop but power LED doesn’t come on. Yet it’s more likely the failure is the power lead from the adapter to the laptop. Your laptop may use a straight plug, like Toshiba and Lenovo, or an “L” connector like some Compaq and HP models, or a special proprietary design like some Dell and Sony adapter. The straight in power connectors probably have the highest failure rate because the cord often droops at a sharp angle.
Try wiggling the cord a few inches back from the laptop jack and and see if the power LED on the laptop blinks. If the LED is unsteady or if it only lights if you position the cord a certain way, either the receptacle in the laptop or the wiring to the connector has failed. If you could choose, a bad cord is a much easier problem to repair, and that’s what the illustrations on this page describe. Sometimes you won’t see any sign of damage on a bad power cord no matter how closely you look because the insulation is unbroken. But the stranded wire inside the insulation could have frayed to the point that it only makes intermittent contact and melts open from current. The cable is normally shielded coax, with the inside conductor soldered to the inside of a barrel connector, and the coax shield soldered to the outside of the barrel connector. The solder joints are inside the molded plastic connector.
	The AC power cord that attaches the adapter to a wall outlet almost never fails as long as it’s plugged in solidly. Laptop power cords usually include a ferrite choke to help prevent RF generated in the laptop from flowing back up the ground shield and turning it into a broadcast antenna. If it’s too close to the molded connector to allow for replacement, I cut it off and hope nobody complains about interference. While you can always strip coaxial cable with a knife, it pays to own a decent wire stripper so you can make a clean job of it. I remove around 1″ of the insulator from the braided shield and then twist the wires together off to one side. Classy technicians may tin the braid with a little solder before proceeding, but it’s not really necessary if the connector has a tab with a hole.
There’s no point trying to reuse the original molded connector unless you are absolutely desperate, in which case you’ll be stuck shaving away the plastic with a box cutter. I’ve had to do this while overseas when I couldn’t find a replacement, but it was a bit of a mess since the ground braid was soldered directly to the outside barrel of the connector on the Toshiba I owned. And it can be tough to resolder manufactured connectors without melting everything because they aren’t intended for multiple use. In the U.S. you can still find barrel connectors at Radio Shack, but bring along the original connector and the laptop to make sure you get the size right. You can often find the exact inner and outer diameter in millimeters (they’re all metric) by searching on the Internet for AC adapter product descriptions for your laptop.
	Before you solder on the new connector, make sure you slide the plastic shell onto the cord in the proper orientation. It won’t fit over the connector after the fact and you’ll have to unsolder it all if you forget. If the shell doesn’t fit onto the cord or your new connector doesn’t include a shell, you can fake one up with many turns of electric tape. I generally leave enough room so the connector can fit into the laptop power jack as far as it will go, but good electrical contact is made before it’s completely seated. In the picture I show the yellow inner conductor of the coax soldered to the tab that corresponds the center conductor of the barrel connector. The silver braid is soldered to the tab which corresponds to the outside of the barrel connector. You can use heat shrink tube over the tabs, if you have it, or even use a couple heat shrink layers in place of a shell.
I tend not to trust the connector shell so I work a little electrical tape in between the two tabs to make sure they can’t get crushed together and short. The trick is leaving enough room to get the shell over it all. The shell can be screwed onto connector since both pieces are threaded. After my first experience when I was forced to carve up a molded connector with a razor blade while travelling, I starting keeping a spare ready made in my laptop case. If the AC adapter cord I’m using fails, I can just cut off the end and splice on the replacement by twisting the wires together. The main failure mechanism for these cords is from the cord drooping down and flexing around when you work on your lap or run the laptop at the edge of a table.
	The problem shown on this page, a frayed or broken power adapter, is easy to diagnose. But most laptop issues benefit from careful troubleshooting before you rush to spend money on parts. The Laptop Repair Workbook is focused on troubleshooting laptop hardware. It includes an introductory section on all power and charging related problems, followed by an advanced flowchart for troubleshooting battery charging and AC power operation. The 191 page printable eBook version can be purchased for instant download anywhere in the world at about half the cost of buying the paperback and paying for shipping.

Tags: laptop power cords
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Laptop AC Adapters – Different DC Connector Types Used For Notebook Computers

Friday, February 3rd, 2012

This set of photos of different AC adapters with the DC connector to the laptop featured in the foreground is a web based illustration for The Laptop Repair Workbook. Replacing the connector on an AC adapter is easy, providing you can obtain one. Some replacement DC connectors are easily found at the local Radio Shack or electronics hobby store, but others are proprietary. You can often find the proprietary connectors for sale on the Internet if you search hard enough, but the easiest source is to take one off a dead AC adapter. You can often find these for sale on eBay. The proprietary three contact DC connector shown to the right is from a Dell. If you have no technician skills, you can usually buy a for around $20.
	Both the Dell above and this Sony to the left feature an RF filter on the cord, very close to the connector. Not all laptop cords feature the filter, which I believe is to prevent harmonic RF noise from the switching power supply from entering the laptop. I used to assume that the filter was there to prevent RF noise from the laptop from escaping via the power cord. From the standpoint of the laptop user, it doesn’t really matter, but I should probably find a definitive answer some day. The center pin connector the Sony is using may or may not be proprietary, center pin connectors aren’t that uncommon, but you have to match the pin diameter and the barrel diameter, and in some cases, the pin length is critical as well.
The Toshiba connector to the right looks like a standard barrel connector, but it has some subtle flat spots. I suspect it could be replaced with the right sized generic barrel connector, though it might end up being a little loose. I can find most barrel shaped connectors for AC adapters in the low voltage connector drawers at Radio Shack. Finally, the connector at adapter at the bottom right is a clever 45 W design from Apple. It puts out 24V on stereo jack style pin. If you have an AC adapter with a failed connector that you absolutely can’t find a connector for, the last refuge is to replace the power connector inside the laptop with a standard connector.
	Recognizing different laptop power adapters is a small part of understanding why your laptop may not work. The Laptop Repair Workbook teaches the basics of troubleshooting laptop problems, starting with an introduction to basic laptop technologies and includes over 100 pages of diagnostic flowcharts with explanatory text for every decision point. You can order the 191 page printable ebook version anywhere in the world for instant download and it will cost you less than the new power adapter than you might not really need.