3x GT2560 not working or smoking

[cpryor]

Hi,

i got a DIY kit and build all and connected the controller GT2560 board and all was working. Printed 1 Peace (;
I left the power supply on and next day the display of the controller was not working.
Got replacement GT2560 and this was also not working
Got third replacement and also not working.

The Problem: The usb cable get very hot with original transparent cable. With other cable the displays get off or very light like the 5V gets to 10V.
The second board booted, but after plug in usb the power controller ic got hot and smoking.
The third board never booted. Perhaps firmware is missing. But same problem. If i connect usb the device will do nothing. Also windows does not find new device in devicemanager.
Third board is Rev. A+. Noticed, that the usb fuse is missing and he gets no power over usb. I shortcut the fuse with a wire and it looked like, he gets overvoltage.

All test was with ext. 12V power Supply enabled. Multimeter shows 12.2V. USB Port tester shows 5V from pc.

What the hell is wrong? I got with the third board new stepper drivers.
2 USB Ports of my computer are now broken.

Do i need to connect all motors and connectors to not destroy the board?

Is getting usb cable hot normal? Is there a general problem with power supply over usb as you changed something with Rev. A+ ?

[cpryor]

Hello,

i found out, that the fault was at the 12V power supply. Between GND and Vcc it was 12V. But between GND and Earth it was also 12V (or -12V if i rotate 220V plug).
So connecting GND of USB with GND of 12V is not good.

Using now a other 12V powersupply.
The first board looks like working (not tested complete). The third is still broken because the onboard powerconverter was smoking.
The third is still missing firmware. But i do get no device in windows. Perhaps Bootloader is also missing.
Is there a trick to get into bootloader?

[William]

The link to it:
http://www.geeetech.com/forum/viewtopic ... 978#p27978

[shadowcaster]

Hi. Have you solve it?
I have the same issue.

[Producer_Phil]

Same issue over here, any solutions found yet? please....

[William]

Same issue over here, any solutions found yet? please....

Have you tried to check the wirings of the mainboard?

[Producer_Phil]

I double checked the wiring its all okay...by now i have disconnected everything from the board just to make sure it is not drawing too much power over the usb port but still cannot upload any sketches....

[William]

I think you can refer to this picture(Normal is 5V)
1.Plug PSU and disconnect USB cable
2.Plug USB cable and disconnect the PSU(3.8----5V)

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