After switching the 3 AAA batteries of my beloved HP 48G calculator, it didn’t turn anymore when hitting the “ON” button in the bottom left corner. I first thought it’s because of poor electrical contact due to poor QA batteries (I noticed the new ones were a fraction of a mm shorter than the previous ones). This might have played a rule in the sudden failure to power on my HP 48G, but it probably wasn’t the only reason.
Here are some “tricks” to try, if your HP 48 won’t turn on:
Double-check that you inserted the AAA batteries pointing with their (+) poles in the right direction (left, right, left)
If the AAA batteries have poor electric contact (particularly the middle one is susceptible to this), cut out and fold some aluminium foil (also called “aluminum foil”; historically “tin foil” was used), and put it where better electric contact to the batteries is needed.
Press the “ON” button in the bottom left corner
If that doesn’t work: press and hold “ON”, press and release the “C” button, release the “ON” button
If that doesn’t work (it didn’t for me): Press the area between the “B” and “C” buttons/keys, then press and release “ON”
If that still doesn’t work (it didn’t for me): Flip the HP 48 over and remove the upper right rubber foot. You can basically just wiggle it a bit and pop it off, there’s no need for special instruments. Underneath, there’s a little hole to reset the calculator. Use e.g. a paperclip, insert one end into the hole until you hear or feel a subtle “click” sound to reset the calculator (please bear in mind that this could also clear the memory). Then press the “ON” button and you’ll be prompted to try recovering the memory, which you should confirm.
At this point, unless it’s a severe error of the board, your HP 48 should turn on again. It might display “Warning: Invalid Card Data” at every start though. You can get rid of this warning message by typing “PINIT” (without double quotes) and pressing the ENTER button (source: https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv013.cgi?read=43990)
If none of the above tips help, your HP 48 probably needs repairing.
It seems to be quite a nightmare to service the HP 48, but there are a couple of videos out there of people repairing a HP 48 SX (disclaimer: know what you’re doing, follow at your own risk):
Recently, my beloved Logitech Laser Mouse G9x showed signs of a broken, i.e. shorted cable. This is a well-known problem with these mice – I had a Laser Mouse G9 before and it suffered from the same problem, and the forums are full of similar reports. It’s also well-known however, that the G9/G9x is one of the best and most wanted fingertip grip mice apart from its cabling weakness (and if you use a mouse for 14+ hours daily or if you’re a pro gamer, you won’t ever want to use any other grip (video)).
Unfortunately, Logitech doesn’t produce the G9/G9x model anymore – though they probably could have easily fixed this weakness in the next revision and even improved some other aspects, like reducing the mouse’s weight. One thus has to find a dealer that still has some G9/G9x mice on stock (and accept a high “connoisseur’s” price, these mice usually sell for around 250 USD – mind fakes!) or go with a not quite equivalent, but similar Alienware TactX mouse (which is based on the G9/G9x and produced by Logitech). Alternatively, one can try soldering and fixing the shorted cable or order a spare cable from China, which are both better options than throwing away an otherwise still working mouse.
This allows me to only emphasize those points that deserve special attention:
Be aware that this repair requires advanced manual skill due to the somewhat unfortunate cabling inside the mouse and the not very maintenance-friendly attachment of the flex flat cable.
I’d strongly recommend ordering new replacement mouse feet as it’s almost impossible to remove the feet without tearing them, particularly if you’ve used the mouse for some years already. To remove the remaining glue, I used ethanol, but something hydrophobic (e.g. straight-run gasoline) might actually work better [Warning: Disconnect your mouse before doing this!].
I used my Victorinox CyberTool 34’s (video) phillips screwdrivers and it worked fine, but if you have thinner screwdrivers at hand, use those, as some of the smaller screws are a bit difficult to reach.
The most tricky thing to reassemble, in my view, is the mouse cable inside the mouse, which is laid out and bent in quite an odd (and scary) way. It’s also the reason why most of the G9x/G9 suffer from a shorted cable sooner or later. You have to bend and route the bundled wires in a way that they neither cover the hole for the screw in the bottom shell, nor the according plastic nut in the upper shell. This puts a lot of stress on the inner mouse cable and requires quite some manual force.
Other not so easy things:
Detaching the flex flat cable/ribbon (for the LEDs in the upper shell) without popping off the little latch (using a flathead screwdriver works though)
Putting the rubber grommet in place again (you need to apply quite some force and the grommet doesn’t really fit very well anyway)
For now, I’ve just quickly replaced the whole cable with a new one, but I will try fixing the old, damaged cable with my new Ersa i-CON1 digital solder station when I find time for it.
What I particularly like about the Logitech Laser Mouse G9x:
Its perfect geometry for finger tip grip users
Good quality of plastics, springs, buttons, wheel, laser sensor
Moderate weight (extra weights removed) as compared to the Mad Catz R.A.T. 7 (extra weights removed) – it’s still quite heavy though compared to other mice, this could be improved (if you intend to lift your mouse often, this is the wrong mouse)
Removable shells
“Hyper-fast scrolling” (this almost seems like a USP of Logitech – I like this feature a lot!)
Good, stable drivers
Has well-placed back and forward buttons with clearly defined clicking points
It’s a wired mouse, there’s thus no need to replace batteries, no risk of running out of battery in the worst possible moment, no added weight, no lag.
– terrible, totally unusable Mad Catz drivers (works well on Mac OS X though using the SteerMouse driver version 4.2.3 and newer – I tested a beta version of it – thanks, Yoshi!)
+ super customizable and adjustable geometry
+ handy precision-aim button (can also be programmed to show Mission Control or the desktop, for example)
+ handy horizontal thumb scroll wheel
Mad Catz R.A.T. 5:
If you can do with fewer or without customization options, the R.A.T. 5 or 3 will likely suit your needs as a fingertip grip user more as they’re lighter and smaller.
If you don’t care about (supposedly) durable, high-quality material, some of the other Mad Catz mice might be good alternatives too (e.g. the hard-plastic mice are generally lighter than those incorporating steel and/or aluminium)
This pro gamer mouse looks very exciting and promising for fingertip grip users – it looks like the perfect mouse to have, also for non-gamers with that grip. I really hope Mad Catz will dramatically improve their drivers though, as terribly bad drivers is currently their biggest weakness.
Many people, particularly gamers, still like this mouse a lot, despite its age. It has a nice geometry and is light-weight (best for palm grips, but suitable for fingertip grip users with big hands too). I once had and used this mouse too (also its predecessor) and liked it a lot. The sensor is quite outdated (but liked by some gamers for its 400 dpi resolution) and used to prematurely die from one day to another. Nonetheless it was the last good mouse produced under the Microsoft brand.
