Subject: Subject: Re: PB 160 - appears dead Electronics is my hobby and power supplies are my "thing". In general I don't open up those "wall warts". I have about 150 of them I've collected over the years, and can usually find one that matches my needs in this pile of tangled wires and plugs. But sometimes I can't, and it's time to pry the offender open and inspect the guts.
I believe you have isolated your problem. Realize that the output from that plug will be somewhat higher than 7.5 volts when you check it with a voltmeter while it's not under load. When it's loaded (plugged into the computer, computer operating) the measured output voltage could be about 9 volts. If it's as much as 10 volts I'd be concerned. With some "wall warts" the components inside are "potted". This means the components are imbedded in epoxy or another polymer. This also means that getting to the individual components is impossible. In extreme cases I have used a hacksaw to (carefully!!) cut the "box" away from the plate that has the plugs that go into the wall. Very carefully!! Sometimes a well-placed screwdriver will do the job. I would not start whacking away at it until totally convinced that there's a good reason to look inside. In high-quality power supplies there is a voltage control regulator... either a fairly large zener diode or a regulator "chip" that controls the output voltage. If it's not potted, then maythe zener diode may be easy to replace. In the best of worlds the zener diode has a number on it that can be "looked up" to learn (1) it's voltage and (2) its wattage. Replacing a voltage control regulator "chip" requires a lot of tender loving care. If you do open it, look for parts that seem to have been overheated. If you work with electronics, the trick is to "load" it with a high-wattage resistor across the output and check for parts that are getting too hot. Then check voltages at appropriate points, etc. I wonder whether the adapter you are using is putting out a good, solid 7.5 volts when it's "loaded"? From: Charlie H. -- PowerBooks is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Enter To Win A | -- Canon PowerShot Digital Cameras start at $299 | Free iBook! | Support Low End Mac <http://lowendmac.com/lists/support.html> PowerBooks list info: <http://lowendmac.com/lists/powerbooks.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[email protected]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/powerbooks%40mail.maclaunch.com/> iPod Accessories for Less at 1-800-iPOD.COM Fast Delivery, Low Price, Good Deal www.1800ipod.com
