Hey all,
First time poster. I have a RepRap Mendel mono. I have enjoyed learning how to create good prints. I recently had a problem, and I wanted to share the fix with anyone else that might have the problems.
I was moving my printer, and unplugged the USB cable from my computer, but I forgot to unplug the other end of the cable from the USB receptacle on the controller board. When I got to my destination, I was sick to see that my cable had caught on something and torn the receptacle was torn off except for a dangling thread.
At first I hoped that I might be able to solder the receptacle to connect back to be board via wires, but then one of the leads broke off as I attempted to manipulate it. To make a long story short, with the help of Ian from RepRap support, I found the following:
--Here is a link to the wiring schematic of the controller board: Controller Board Schematics .
--Here is a closeup picture that shows how the receptacle is normally attached. It is the part on the bottom with a yellow-colored membrane on its surface
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I am fairly certain that the receptacle is a "micro B" type connection. The pins are numbered from 1 on the left to 5 on the right, as shown here:. And here is a good reference for the various USB connections.
(FYI: Pin 4 doesn't do anything. I'm not going to into much of a discussion about this.)
I was initially confused about pin 5, as I couldn't trace that it did anything by just looking at the board. Notice from the image that pins 1-3 have surface wires running away on the controller board to other parts. Even the schematic didn't seem to show pin 5 doing anything, as seen below (Note: this is the schematic for the same part of the controller board shown above):
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I then noticed that it was supposed to be connected to ground, as shown on this part of the schematic:
![]()
I wasn't sure exactly how to connect pin 5 to ground. I thought that the large blocks on the schematic that represent the attachment points for the usb receptacle would be ground, but it wouldn't work when I attached there. With testing with a multimeter, I determined that one of the empty connector holes did connect directly to ground. On the schematic diagram, I used the open hole below and to the right of the bottom right large attachment block for the usb receptacle. There are two holes side-by-side. The I used the empty one on the right. See also photo below for placement. There are likely also many other places that a ground wire could have been attached.
I used the fine wire that came with my RepRap kit, individual strands of the ribbon wire that was provided. When the metal strands are neatly twisted, they pass nicely through the connector holes on the controller board. I am not a super good solderer, but I was able to get the get the job done. I didn't think that if I tinned the wires before hand, that I would then be able to pass them through the holes. So left the wire a bit long, applied the solder onto the protruding tip on the backside of the board, and then quickly pulled the wire and solder back a bit so that it cooled and made a firm connection. Here is a picture showing the connections. It is difficult to see exactly where the wires are connected. Comparing to the schematic above will help.
![]()
After I had the wires connected to the controller board, I next needed to connect those wires to the USB. I couldn't use the receptacle I had, since one of the wire leads had broken off, so my best option was to hard-wire the cable directly to the board. I opened up the micro end of the USB cable, and found 4 coated wires, and some surrounding shielding wire. And mixed in with that shielding wire was a copper ground wire. To determine which wires to connect to which, I referred to this diagram of the A-type connector, which goes into the computer. Notice that there are only pins 1-4. The metal casing of the A end connects to the ground wire (pin 5) on the controller board.
I got it all connected, and Hallelujah, it worked! I firmly attached the fragile wires to the printer frame with zip-ties to prevent further problems. I have been able to connect to the board from my computer and print more 3d objects out.
Here is a large picture of the overall fix.
A word to the wise. I recommend that other users with this same printer arrangement to do SOMETHING to secure the USB cable to the frame as a shock guard. A simple zip-tie would work, or someone could create some clip that is more easily reversible. I hope I am the only one to ever have this problem, but it seems that without some sort of guard that others will face the same horror I did.
Best Wishes,
Kevin Toppenberg
First time poster. I have a RepRap Mendel mono. I have enjoyed learning how to create good prints. I recently had a problem, and I wanted to share the fix with anyone else that might have the problems.
I was moving my printer, and unplugged the USB cable from my computer, but I forgot to unplug the other end of the cable from the USB receptacle on the controller board. When I got to my destination, I was sick to see that my cable had caught on something and torn the receptacle was torn off except for a dangling thread.
At first I hoped that I might be able to solder the receptacle to connect back to be board via wires, but then one of the leads broke off as I attempted to manipulate it. To make a long story short, with the help of Ian from RepRap support, I found the following:
--Here is a link to the wiring schematic of the controller board: Controller Board Schematics .
--Here is a closeup picture that shows how the receptacle is normally attached. It is the part on the bottom with a yellow-colored membrane on its surface
I am fairly certain that the receptacle is a "micro B" type connection. The pins are numbered from 1 on the left to 5 on the right, as shown here:. And here is a good reference for the various USB connections.
(FYI: Pin 4 doesn't do anything. I'm not going to into much of a discussion about this.)
I was initially confused about pin 5, as I couldn't trace that it did anything by just looking at the board. Notice from the image that pins 1-3 have surface wires running away on the controller board to other parts. Even the schematic didn't seem to show pin 5 doing anything, as seen below (Note: this is the schematic for the same part of the controller board shown above):
I then noticed that it was supposed to be connected to ground, as shown on this part of the schematic:
I wasn't sure exactly how to connect pin 5 to ground. I thought that the large blocks on the schematic that represent the attachment points for the usb receptacle would be ground, but it wouldn't work when I attached there. With testing with a multimeter, I determined that one of the empty connector holes did connect directly to ground. On the schematic diagram, I used the open hole below and to the right of the bottom right large attachment block for the usb receptacle. There are two holes side-by-side. The I used the empty one on the right. See also photo below for placement. There are likely also many other places that a ground wire could have been attached.
I used the fine wire that came with my RepRap kit, individual strands of the ribbon wire that was provided. When the metal strands are neatly twisted, they pass nicely through the connector holes on the controller board. I am not a super good solderer, but I was able to get the get the job done. I didn't think that if I tinned the wires before hand, that I would then be able to pass them through the holes. So left the wire a bit long, applied the solder onto the protruding tip on the backside of the board, and then quickly pulled the wire and solder back a bit so that it cooled and made a firm connection. Here is a picture showing the connections. It is difficult to see exactly where the wires are connected. Comparing to the schematic above will help.
After I had the wires connected to the controller board, I next needed to connect those wires to the USB. I couldn't use the receptacle I had, since one of the wire leads had broken off, so my best option was to hard-wire the cable directly to the board. I opened up the micro end of the USB cable, and found 4 coated wires, and some surrounding shielding wire. And mixed in with that shielding wire was a copper ground wire. To determine which wires to connect to which, I referred to this diagram of the A-type connector, which goes into the computer. Notice that there are only pins 1-4. The metal casing of the A end connects to the ground wire (pin 5) on the controller board.
I got it all connected, and Hallelujah, it worked! I firmly attached the fragile wires to the printer frame with zip-ties to prevent further problems. I have been able to connect to the board from my computer and print more 3d objects out.
Here is a large picture of the overall fix.
A word to the wise. I recommend that other users with this same printer arrangement to do SOMETHING to secure the USB cable to the frame as a shock guard. A simple zip-tie would work, or someone could create some clip that is more easily reversible. I hope I am the only one to ever have this problem, but it seems that without some sort of guard that others will face the same horror I did.
Best Wishes,
Kevin Toppenberg