Siemens SL45/SL45i modifications

What you need:

• The cheapest headset you can find, since we're only going to use the lumber connector. Make sure that all the necessary pins are available. (check the schematics to know what pins you need)
• A broken walkman, or any other device that has a mini-jack plug soldered to a pcb. The ones you find in a sound-blaster are too high, so no need taking your computer apart ;-)
• soldering iron and solder
• some rather thin wires
• cutter knife
• super glue

How do we do it:

First of all, open the lumberg connector. Mine has a couple of clips holding it together, so it opened rather easy. Desolder the mic and speaker combo. Next, take your victim and desolder the mini-jack. Now you'll need to do some cutting and measuring. Find a way to fit the mini-jack adapter in the lumberg connector. I had to remove some of the closing-clips and fold the pins on the mini-jack down. After doing this, you should be able to get everything in the connector. Now you need to find out what pins on the mini-jack are left, right and ground. If you're lucky you'll find that marked on the mini-jack, or on the pcb. I wasn't lucky so i had to find an onther way to figure it out. I soldered some test wires to the lumberg connector. You'll need pin 2 for left signal, pin 11 for right and pin 12 for ground. These pins are counted from left to right when you put the lumberg in front of you with the 'soldering side' pointed towards you, and the flat part of the connector on top. (So the bump that holds the clip to secure te connector in the phone is at the bottom.) Now we need to tell our phone that there is a headset attached to the phone, so bridge pins 8 and 1 with a wire. If you got all those wires just play a song on your phone and try to touch the pins of your mini-jack-connector until you know what every pin does. Now you'll need to solder the wires to the pins. Make the wires as short as possible, since the space in the connector is really cramped. If you got everyting in there, have a test-listen before glueing it toghether. Voila!

I saw the LED flashlight on your web site and had to make one. I thought I would try to make the brightest I could with a button you press to make the LED come on. The advantage of this is you don't have to unplug the whole connector to turn the flashlight off.

The LED is an extreme brightness Nichia 5 mm White (one of the brightest on the market I believe) and cost £2.99 each! It's typical operating voltage of the LED is 3.6 volts. This is perfect because the Sl45 battery outputs at 3.6 volts! It also only uses a maximum of 30 milliamps so it uses hardly any power (I've used it for long periods)! It has a large beam radius of 50 degrees so it produces a good overall area of light rather than a little bright spot. It is approximately 2.3 times brighter than the original posted on the club-siemens forum. On Nichia's web site they have some incredibly bright white LED's that are 3.5 times brighter then the one I used, but they are very very expensive and very difficult to get hold of.

The push button came from an old VCR front panel. The SL45 connector came from a personal hands free kit I bought for £1.00 from Poundland. To look at it you would swear it was an original Siemens accessory!

I too faced the problem of the SL45i switching off for a long time and traced the problem to the way the battery sits (two joints at the bottom and one clip at the top). This allow the battery to bend a bit while handling and the battery contacts with the phone breaks. I tried multiple batteries, all had the same problem, seems to be a manufacturing defect. I tried stuffing paper as people suggested between the phone and battery to prevent the battery from shaking and it didn't work. I finally stuffed a small paper inbetween the back cover and the battery where the 3 contacts are. (You have to pry open the gap with a screw driver). This lifts the battery contacts a bit closer to the phone and seems to solve the problem. My phone has not gone off for the past 2 weeks.