very strange disconnection when i open lights

hello, i'm printing with repetier and ramps 1.4 on a prusa i3.
there were some times that the printer would disconnect and wouldn't let me reconnect without resetting the arduino and disconnecting the usb cable.
but today i just understood the exact moment it disconnects, let me explain.
in the room there is a movement sensor that opens two neon lights in the room, when i enter the room at night the lights open and the printer disconnects.
now, it happened for like 4-5 times and now i'm sure, IT DOES HAPPEN WHEN I ENTER THE ROOM AND THE LIGHTS OPEN.... it doesn't always happen, but when the printer disconnects it's when the lights open...
i don't know what is happening, it's really strange for me, the computer keep working without problem, it just disconnects and everythings stops but the printer stays on maintaining the temperature...
any ideas?

p.s. the ramps controls the ATX power source and the standby power is also connected to the 5 volts delivering power to the arduino when the printer is off

Edited 1 time(s). Last edit at 06/20/2014 04:49PM by euge9522.

[www.osram.it]
those are the lights

that curent whats neon light take drop voltage when they light on and they are on same circut like yours outlets wher is connected yours printer.If you cant use diferent outlets use battery backup for yours printer or better power source what can work with volatge drop down

First those are fluorescent lights not neon. When they start up they actually produce a magnetic pulse and that can interfere with the USB data. I have the same issue with a utility lamp near my printer. It's a combination of proximity and type of lamp you need to either switch light types (LED or incandescent) or move it much further away. I suppose you could also try a heavily shielded (with shield hooked to ground) USB cable but you may also need to shield the printer board.

i thought about voltage drop, but i don't think it's the case because all ATX likely have enough capacitors inside to compensate for this little thing(consider then that arduino has like 3 different power sources).
but yeah, that thing of the magnetic pulse inspires me! ahaha, i'm now trying to print with a laptop and a MUCH shorter wire, for now no problems... i need to search for that heavly shielded wire but that one that i'm using now is about 20% thicker than the one before(actually the one before was a really awful wire...3 mt long and low quality...)

I was having a similar problem that I solved simply by replacing the USB cable.
The old cable was of bad quality in terms of insulation (very thin). The new one, besides being much better insulated comes with ferrite chokes on both ends. It was a life changer.

I use to have this problem when I was printing in the living room. Did some googling and decided to take some actions, after which the problem when away.

- moved the printer to my room where there is less interference
- upgrade to a higher quality usb cable with ferrite choke
- print from sd card instead

No longer face the problem but at the same time can't tell which was the critical factor in causing the problem.

Quote
chngyian
I use to have this problem when I was printing in the living room. Did some googling and decided to take some actions, after which the problem when away.

- moved the printer to my room where there is less interference
- upgrade to a higher quality usb cable with ferrite choke
- print from sd card instead

No longer face the problem but at the same time can't tell which was the critical factor in causing the problem.

Thats easy to find out though. Just reverse steps from your process. I think just printing from SD will already make a huge difference

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http://www.marinusdebeer.nl/

just printing from a laptop, with a shorter wire(i don't really know how much better the quality is, but slightly better) solved pretty much completely the problem, and it frees my computer to do other things(also the laptop can be closed and keep printing, it doen't even look on ahah)