How to know if Arduino is working?

I bought the RAMPS and Arduino Mega 2560 and 5 stepper drivers. I plugged in everything to the pc and everything was working perfectly. I installed all my arduino drivers easily. Then at my friends place when I plugged the psu to the mains and turned everything on, 1 of the stepper drivers started smoking from the chip attached to it and got fried. I think it was  due to too much voltage. After a while removing the burnt driver when I connected my Arduino to the pc, the pc does not find its hardware. Only this 1 light stays on and nothing happens. I don't see that there is any physical damage to the board.. but there might be .. I am not sure what to do now.. I want to know if I can check wether the board is still working and how can I connect it to the pc?

iceng2 years ago

Sorry to hear. I know how gut wrenching it feels when there is damage beyond your ability to fix. A high voltage can do massive semiconductor damage.

The pcbs you show are several layers hidden from view and a burnt trace

( always a possibility with servos ) may not be obvious to correct.

In my time we changed out the ICs but these days they are surface soldered and you are reduced to exchanging boards and it sounds like the serial interface to your micro is damaged and the only way to verify that is try a new PCB and go from there.

If there is enough voltage to cause a driver chip to fail and cause heavy current to flow with ensuing heat to the point of smoke, then there are very probably other damaged logic ICs.

SowmenD (author)  iceng2 years ago

I want to know how I can know weather the Arduino is broken or the RAMPS.

-max- SowmenD2 years ago

I'd say plug it in, paying attention to the voltages again, and see what gets hot and what doesn't. The RAMPS board I thing appears to have some huge PTC protection (resettable fuses) along with some serious TO-220 devices. One of them is probably a voltage regulator. My guess is that, if you did not kill a trace on that board, then it is probably fine. A really simple ohmmeter can help you trace out all the connections, if you have a reference, or know what should be connected where.

Do the small chips get hot when powered? If the board acts like it is not powered, (other than the red LED) like as it is it is not even plugged in, then it could be that you killed the voltage regulator, and it took all the force and saved the sensitive microcontroller. As long as power did not bypass it. A voltmeter or oscilloscope can be used to quickly see if there is voltage to the chips and things. If the meter is reading random values that keep drifting all over the place, then that rail is is probably floating and the voltage regulator died.

To avoid this in the future, get a decent multimeter, don't pay less than $20 for one if you can. I have an amprobe AM220, and an UNI-T UT61E meter. They are great mid range meters, the UT61E is better suited for signal electronics and low voltage stuff, and the AM220 is a good general purpose entry-to-mid range meter. A true electronics hobbyist should have at least 2 meters, and a cheap used analog oscilloscope for debugging. I picked one up off craigslist for $30. 2 channels, and 30MHz BK precision. That can help diagnose problems. And of course, a decent power supply. Preferably one with a current limit function. You can build one yourself if you want to!

iceng SowmenD2 years ago

Perhaps both, but you cannot talk ie recognize the Arduino alone (yes ?), so as a start it is the Arduino. Once the Arduino is taking programs, then you can modify the sadw to see if the individual modules respond or do not.

Also invest in a $5 meter and measure voltages before you apply them to your electronics. In fact it has a continuity ( ohmeter ) function that can determine if any traces are blown out in that orange shield if you have the wiring schemetic.