I have recently acquired several broken Swann Night Hawk SW231-WOC wireless security cameras and figured i would document the tear down process and anything interesting i might find. My goal in this project was to satisfy my curiosity, try my hands at fixing them and perhaps even learn something in the process.
Here’s how it starts:
And here is how it ends:
Dissasembly is very easy – front of the camera unscrews by hand and the rest is all regular phillips screws:
The first board that you see when you unscrew the front of the camera is the LED board. There’s an o-ring (not visible on the photo) between the front and the back of the camera which provides protection against elements and it more or less does it job – inside of the camera case look clean and water free. Main elements on the LED board are the 12 infrared LEDs connected in series of 3; light sensitive resistor which turns LEDs on in low light conditions; and 2 position DIP switch marked “ON KHS22” which selects the transmission channel (1 through 4) . The back side has a 3 pin device marked Y2, a 5 pin chip marked 3272 – probably an op-am, and a variable resistor to adjust sensitivity. Board is marked with AEE, V812IC10:
The second board is the image sensor and 8v to 5v conversion board. It is marked with V801CV28. Notable components include image sensor – no markings on top but based from Swann’s specifications is a 1/3″ Color CMOS, 510 x 492, 380 lines sensor in a 48-CLCC package rated for 5 volts. Sensor is covered by the focusing cover which allows adjusting sensor to lens distance via rotation of the lens holder. On the back of the board there’s a 14.318 MHz (NTSC sampling frequency) crystal. Voltage conversion is done via 75L05 5v voltage regulator and a 10 uF, 5v capacitor. In the entire camera only LEDs are using supplied 8v from the power supply, rest of the components use 5v supply:
The third board is the RF board and is marked VT24A0X4 040315. This board is connected to video sensor board via yellow data wire, red (torn out on the photo) and black power supply wires. It is also connected to the channel selection switch on the LED board via white and yellow wire and to the Microphone board via the white data wire. Board contains following chips: “bj8p153snj ar03-a 0812” which is a 2.4Ghz transmitter (channel selection switches are soldered directly onto 2 pins on the chip); 17.734475 Mhz crystal which i could only identify as PAL related frequency. On the back there’s “E07SL E1C744 M52” which i found is described as “Single Serial Input PLL Frequency Synthesizer On-Chip 2.5 GHz Prescaler”. My RF knowledge is very limited so i did not pursue this board any further:
Fourth board is the microphone and power jack board. Unlike the main camera case this one is not protected via o-ring and shows quite a bit of water damage. I consider this a major flaw in design as at least one camera in my possession failed because connections on the circuit board rusted out. The board contains a microphone, a side switch perhaps for enabling/disabling audio and something with 3 pins and 4th large ground marked “8A 804”:
I have also acquired a cheap Swann Receiver:
Out of 4 cameras that were broken i have managed to fix two. First one had rusted out power supply connection and what looks like a bad case of electronics-rage: all camera innards were twisted and ripped but then stuffed back and closed (why?). After re-soldering all wires and patching rusted out connections on the microphone board, camera came alive once again. Another camera had a bad transmitter. I figured that one out by connecting two cameras to the same power supply and rewiring the sensor of one camera to use transmitter of the other. After installing good transmitter board from another camera this one started to work as well. The other 2 cameras seem to have bad sensor board/chip. One of them has a short (12 Ohm) between power and ground which i was unable to trace and another just doesn’t output anything. Perhaps i can give it a try later when i am more experienced. If some one out there has any ideas or the pointers on how to decode these “Y2” and “8A 804” devices please let me know.