Archive for December, 2006

Bluetooth

Thursday, December 21st, 2006

Today I decided to break apart few bluetooth headsets. I have 3 models, all made by Logitech. Most of the headsets have same, typical damage- the mic wire is broken. The problem is even described in manufacturer’s webpage. Just if you turn microphone around the headset and use some force, it breaks very small stopper and turns around. And small wire from main PCB to mic is broken.

I tested the devices with my old Nokia phone and computer using microsoft usb bluetooth adapter from mouse and keyboard. Computer detects Logitech headset, but didn’t install the “audio device”. In Logitech pages the problem is described like: “normally all devices are installed automatically”. And not a single word about “abnormal” situation. I think it is microsoft fault- microsoft bluetooth stack is lacking some “standard” elements. You need to install Widcomm drivers.

Inside the headset is nothing interesting…

bluetooth

On the other side of PCB is only quite big Liion cell and contacts for charger.

Main element in the headset is CSR semiconductors chip. It is MCU, DSP, audio device, bluetooth in one chip. On the right, emphasized PCB you can see something like EMI shield, but I thing that it is only some leftover from some bigger shielding.

bluetooth

Other components are only for charging, LEDs management and audio amplifiers.

4 Mpix camera

Thursday, December 21st, 2006

Typical simple digital camera, so called soapbox, is quite expensive (in our country) device and it is carefully handled by user. And nobody opens the camera body just for fun. All digital cameras are quite complicated electronic devices and more, photo-camera with moving objective lenses is quite complicated mechanically. Also, when opening such device at home, always some dust manage to get inside it. I am getting very nervous, when I put last screw to its place and discover horse hair somewhere inside the lenses or behind small LCD…

But I received about twenty damaged digital cameras for testing and now situation is much brighter as circumstances are new: no need to repair, if I damage something- no problem, if I fix it, I can keep it for myself. I have Samsung Digimax A4/401/400/430 and some LG models.

4Mpix

… so the repair procedure is very simple. Test all devices and sort them according damage. Mechanical lenses damage, electronics not responding, bad image due to damage of CCD and etc. Now it is time to make some swapping :) .

4Mpix

This damage is very simple and very easy to repair:

4Mpix

Just swap LCD with other one and everything is ok. There are more problems with cameras without moving parts. Most of them didn’t switch on. But one was with damaged buttons (need to re-solder one connector) and other was with zebra-like image (the CCD sensor is damaged, or just some leg unsoldered). So these were repaired.

LCD of the camera is LTV180WQ LCD and Casio 5D16BRD…

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Top video cards to crash

Thursday, December 21st, 2006

From big pile of bad computer stuff I selected three cards to destroy. The selection criteria was a bit strange: the add on card were big and heavy, solid design and maybe expensive.

top AGP VGA cards

So, here we have:

Radeon 9800 PRO 128Mb with passive cooling: heat-pipe and double large heat-sink.
Winfast PX6800GT with heatpipe, cooler and double huge heatsinks.
Siluro GF4 Ti4200-8X OTES, 128Mb with turbo cooler, heatpipe and small daughter board.

All card used double card space. Before breaking apart these cards I inserted them to old AGP computer with … DOS. Two cards seams working, third didn’t go to the slots, as seams it is low voltage only version.

Damn, if they work, I need to test them before breaking apart. In fact I selected them to cut the cooling system from them and adapt it for better cooling of my X700 card.

Images from internet:

:)

Programming Cable for Kenwood

Tuesday, December 12th, 2006

I have few Kenwood TK-760G-1 transceivers (two-way radios) and they all were programmed to one channel and all other features were locked. In the internet and in local newsgroup I collected various software for Kenwood programming. All I needed is programming cable. My first attempt was with MAX232 adapter borrowed from Atari SIOP cable. I managed to get “-PC-” message but nothing was working. At last, I build cable exact like in some Russian internet pages. Also I hear rumour, that for programming I must use very old and slow computer. In local trash I selected P1 running at 233MHz. I soldered the cable, connected and everything is working!

kenwood programming interface

The circuit diagram for programming cable is something like this:

kenwood programming interface circuit diagram
Big image for printing.

As always, some components were not available in my closet, so I used something looking like needed :)
I didn’t find (in fact, I even didn’t tried to find) original transistors needed, so I replaced them with refurbished ones from old ATX power supply: A733 and C945 pair.
I didn’t used C2 capacitor. Also, R3, R4 and R5 resistors are only near needed values.

Cable pinout. At Kenwood 8 pin connector like LAN (Ethernet) port or 6 pin: GND- 3(2), RTXD- 4(3), RRXD- 7(6). In brackets you can see pin numbers for 6 pin socket.

As I understood from the description, this adapter can be used to program other types of radios. And not only Kenwood, but Motorola and other brands. BTW, this cable is called “universal programming cable”.

Original idea, schematics from Hungary by Gyula HA7JCA.