Failure in arduino/ramps damaged laptop

Hi all. Today was... BAD day.
I was finishing a print, and exactly when the print was finished I was looking how the extruder was homeing the X axis and at the end I heard (I think it was) a littel bump or may be was the sound of short curcuit or something, the printer LCD went completly "iluminated" (actually I discovered later that the screen brithness went to 100% and I just fixed from the controller behind the lcd screes, it is a reprap smartcontroller) and the laptop turned off (the printer was connected to the USB.
My laptop did not respond any more, I coudnt turn it on. After some curseing, I desasembled the laptop and discovered that the USB circuit where the printer was conected was somehow damaged becase disconecting that module let me turn the computer on, so yes, the USB module in the laptop was somehow damaged.
After some happines I went back to the printer and tried to print useing just the LCD controller. It didnt work: The heater was working, the heated bed was working, fan control was working, but when I tried to move any axis it didnt respond: teh X,y,Z and the extruder motor. I dont belive for 4 motor can fail at the same time, si I guess the arduino board or the ramp board broke.
I tried a stupid experiment: I conected the printer to the other USB port in my laptop and when I did that the laptop turned off inmediatly, this time I inmedaitly pulled out the usb cable and fortunatly no extra damage to the laptop.

Daes anyone have an idea of what could have happened?
And most important: how is it posible that the broken arduino board could couse damage to the laptop
And even more important: is there any way to ptect me in the future , I mean, some kind of USB filter/fuse?

Thanks in advance

Damn man, that sucks massively. Glad the laptop still works though.

While you can prevent killing a USB by buying a good computer, connecting something that can dump 5+ amps and 60+v in to your PC is a risky thing. The risk is low, but statistically now and then something catastrophic will happen.

There is always the chance that multiple chips will fail and something will port either the printers power to USB, or a driver blowing up will send a voltage spike through the Arduino and to everything else. Everything else includes anything connected to the printers power supply and in many cases even on to the main power line of your house, enough to trigger surge protectors connected nearby.

The best way to avoid this is to use a good USB hub, that will at least put something else in between printer and PC.

you can buy a usb isolator for this very purpose they are recommended for usb scopes and cost about $100 for the one I found at Link Instruments

I am electronics technician and this is caused by leakage of AC power sources. That is, one or more fonts are with low mains isolation (which is compounded by power surges from overloads, rays, etc.). USB isolators as recommended above, avoid accidents, but do not solve the problem itself. For this it is wise to use a good grounding in the center pin from all power sources (printer, laptop, etc.).

Top tip from Roger, definitely have to say a USB isolator would be the absolute best way to prevent this from happening.

I looked on ebay and was surprised to see some cheap isolators going out for ~$15 from china. Not sure of the quality but if you can't afford the $100+ for an expensive one then maybe that would be a good bet too.

If you have an external controller just use that. The risk of something going wrong when the printer isn't doing anything (heating, printing ect) is quite low so updating a controller by USB now and then should be safe.

USB port failure from plugging in damaged USB equipment is very common, sadly.

Usually the computer (laptop or whatever) is usable afterwards, but it's a component level repair job to get the port operational again. Very often Mr Southbridge chip needs replacing.

Trad serial ports always had opto isolators to prevent this happening, so one way of avoiding it is - use a real serial port, not USB (needs desktop PC though, many laptops don't have).

Or, instead of an Arduino Mega, use a Raspbery Pi with a real USB port... snag with that is, last I head you were limited to one extruder. There are other dedicated controllers that avoid using Arduino, whether they got opto isolated USB ports, I don't know.

Arduinos were designed for development, not for manufacturing.

Edited 1 time(s). Last edit at 10/19/2016 12:59PM by DragonFire.

Thank all for the information and feedback. So far I have: a good USB hub with, I dont rememeber the name of, a kind of overpower protection. And I will continue useing the printer through the LCD controller... and keep the conection to the laptop more restrained.
Thanks all of you!

Hello!
anyone know the real FTDI chipset code installed in MKS BASE v. 1.4 ???
i need replace it ...THK a lot for Help...