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Here's the attached image: image
(source: gsmsolutions.ie)

The CA-50 was used by Nokia to program newer phones. Nokia phones from around 2008-2011 feature this port for flashing.

I noticed the USB side is unusually longer. It is even bigger than the USB pen drive I hold. Does it hide any kind of microchip beneath it?

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    if you don't mind losing the cable you can cut it open and see ;) Nov 23 '16 at 9:36
  • Ok, I did just that, and it does contain some circuitry, it looks exactly like the image at this link. The cable, when connected without any device at the other end, is detected by the computer as a serial communication port. I think this circuit is something designed by Nokia to help reduce additional circuitry on the phones that can be connected, and they work only with the Nokia PC Suite. Any brighter minds here might crack the code on its real purpose. Nov 24 '16 at 15:41
  • You aren't really going to get much more info from the hardware given that it's a little magic COB. Nov 24 '16 at 15:46
  • Yeah, maybe. And it is a cheap knock-off too. The original Nokia cable has different internals, not a COB but SSOP. Luckily, I just found a site with the same discussion here, the cable I've cut looks exactly like this on the inside. Nov 24 '16 at 15:56
  • I am yet to understand its original purpose. Nov 24 '16 at 15:57
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Older Nokia phones use a serial (db-9) cable so if this cable supports flashing it likely includes a usb to serial converter (eg ftdi chip)

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  • Why exactly is serial converting needed when the USB itself transfers serially? Nov 26 '16 at 17:23
  • @ShubhamDeshmukh USB does not use the UART protocol
    – Igor Skochinsky
    Nov 26 '16 at 20:26
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If there is any chip inside the cable, it will use the 5v line as power supply. So, you have to measure resistance from gnd to 5v and compare it with another cable. Usually, the resistance is so high it's undetectable by a normal tester, and this also means there's nothing more than wire and plastic inside (for sure in any normal device). Also, make sure to measure resistance backwards and forwards (I mean, swap the probes), because it is a semiconductor.

You can measure also the data pair.

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The USB cable might have contained a chip to handle some special I/O, but I don't think it was anything special. In fact, there is a third party cable with a smaller male USB end which appears to work as intended.

Cable

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