Gen7 1.5 (repetier) loses connection

Hi

I'm very happy with my Gen7 board and my printer. I'm using repetierHost and Firmware and everything works fine. This is, until it suddenly loses connection. It happens midprint and random, every time. In the log I can see that the reason it stops is, that there is no or an incomplete response from the board. The board keeps maintaining temperature and tries to send something every second (according to repetier it is a "wait").

I am not a 100% sure, but I would argue that another USB cable did make it a bit better/later. I would also argue that dry runs (without any heating and extruder) it is better.

Where could I look for the reason and do you have any idea what to do about it?

Does this happen with another firmware, too?

I mean, influence of electromagnetic radiation (EMF) is always possible, but this is usually very random. Like it happens after minutes or after days, in no particular pattern. In case of EMF, housing the electronics in a grounded metal case would help.

Trying another firmware would help to rule out a software issue, though.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

I tried Teacup, and besides other problems it happened also.

I talked to repetier about this and he said he had another case where someone used wrong capacitors, but thats not the case for me, I guess. Actually, I cant really say it is not a firmware/host problem, but it really does seem that it isnt, since both, board and host say "waiting".

I'm going to try an even better USB cable an lookif it helps.

So it's not a software problem.

FWIW, here's another thread with similar trouble: [forums.reprap.org]

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Ok, no luck with the 4th cable. It happens very random when I'm not in the room, so I don't think it is ESD. I'm going to check the solder joints on the capacitors. Maybe I can manage it to power the board by the same USB cable and totally remove everything like motors and sensor.

I did some research today, I hope you can read something out of this:

I disconnected everything. Then, I soldered a wire from the USB 5V to the 5V pin of the ATX connector. Then, I only connected the USB. I put the board into a special debug mode, in which it only accepts commands but doesnt do anything with it. It crashed like it did before. So I can say it is no ground loop, no ESD...but what is it? I also checked all the solder joints again with my multimeter.

Make sure the metal housing of the USB connector is soldered to ground, too. Without that I had failures on my first prototype.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Just checked it with my multimeter, it is soldered to ground.

Quote

Then, I soldered a wire from the USB 5V to the 5V pin of the ATX connector.

Not a good idea. These two 5Vs can be slightly different and if you connect them anyways, unwanted currents will flow.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

I just soldered this for testing purposes. I wont connect the ATX power supply while this wire is soldered. It is just there to test the board without the power supply plugged in.