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Author Topic: 7Links PX-3615 - 675 with open video device error  (Read 9902 times)

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September 11, 2015, 08:57:11 am
Hello all

I am writing to you because I am at the point where I cant say which direction is better for finding the error in my device. So perhaps anyone has some more detailed information or recognizes the CMOS Sensor Board and can provide some info about it...

I got a used 'defective' 7Links PX3615-675 Wireless Pan & Tilt IP Camera which was distributed by the german seller Pearl. (Un)fortunately the Bootloader was ok but partititions 6 and 7 were gone, so there are no recovery dumps from *this* cam available.

After the first days of googling I thought this Cam is an exotic one, but after comparing the details of the housing, pcb and chipsets i was sure that its an Instar 301X or Apexis J011 Clone. The MAC manufacturer ID and the 4MB Flash were good signs. But none of the FWs I found and tried were working. Neither the 17.22.2.XX nor the 17.37.2.XX which are some of the original firmwares this cam was shipped out here in germany (Attached one Bootloader output)

Later I read that many firmwares (eg Foscams FI8908w) are running well on the PX3615 (no info about -675 or other) so am at the point where I am very sure that my CMOS sensorboard is faulty.
I tested all the wires to it and checked the 5V Vcc on it, everything is ok...

Now I have two general questions: Is it possible to detach the sensorboard from the ARM PCB and simply solder a USB wire to the 5V D+ D- and GND testpads on the sensorboard, in order to check its function at the PC ?
And I read about the rare possibility to reflash the IC on the sensorboard, is there a chance to do this in my case ?

Anyway, i am thankful for every hint I can get for the PX3615-675 !
Thanks in advance !


By checking pictures of any kind of IP Cam PCBs i finally make out my pcb caption right... I misunderstood J011 as some kind of connector caption, like J4 and J11  ;D  So Apexis is definitely involved in this cam or at least its mainboard.

The next thing is the controller chip on the sensorboard. It is obviously a Pixart PAP7501 and when i am informed correctly this means i can not flash a new firmware onto it  :(
« Last Edit: September 11, 2015, 01:01:52 pm by amplidude »

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September 14, 2015, 03:00:03 am
yes you can connect the sensorboard directly to a PC via usb.

look for some of my very first posts, there should be some with the same board mentioned accompanied by fitting fw (maybe also whole flash dumps, I'm sure I still have them)

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September 16, 2015, 07:07:08 am
Hey schufti, thanks for your quick reply ! I think I found your post...

You are absolutely right, your hootoo pcb is more similar to my board than any other Ive seen on the internet the last weeks! Small improvements at V2.0 but i can swear they were build in the same factory...

Your attached romfs.bin is equal to the .img, right ?
And does the linux.bin need to be compressed with some unix application ?
I tried with ordinary WinRAR and flashed both. It worked so far until the well known open video device error appeared.

Then I had enough of try and error, I soldered the sensorboard to a USB cable, plugged it in and... nothing happened. Hopefully switched D+ and D-: Nothing. Measured Vcc onboard: 5V.
The board itself consumes around 70mA (the Pixart Chip is rated < 100mA) so this is fine but there was no reaction on the pc.
A colleague has currently borrowed my oscilloscope, so when its back I will take a closer look at the sensorboard signals.
Chances are getting smaller and smaller to re birth this cam as a cam.

But... please let me know if it is possible to remove the 'open video' command by hand in an extracted version of the firmware ...or if you know if anybody already did so.

I really dont want to throw a wireless webserver with IO Interface away, even if that means that I once again have to learn linux almost from the beginning ;D

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September 17, 2015, 02:04:35 am
unfortunately all the initialization, serverstarts and such happen in one big binary blob.
Somewhere on the board one can find a little documentation of attempts to reverse engineer that up to the level of disassemled machinecode. If you are brave (and lucky) you can patch the video init away.
Or you try to transplant a camera module from a cheap fleamarket shot.

p.s.: and yes, it is apexis (OEM or b-grade)
« Last Edit: September 17, 2015, 02:10:57 am by schufti »

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September 18, 2015, 08:39:04 am
I really have to thank you once more for sharing your knowledge, I definitely will give both options a try!

But there might be a last chance, I found a second used PX3615-675 for a small price and ordered it. The label on the bottom is from Pearl too, but slightly different. Waiting impatiently for its arrival because finding errors with a functional spare unit is much more fun as without  :D

I will then post the next results.