Rate8x
1
So I’ve had my Maker Select III3 Plus for about a year and it’s been wonderful up until 2 weeks ago.
I’ve never heard of anything like this.
Whenever I connect the printer to the USB port, the hotend begins to heat up.
Now, the computer recognized the printer and I can control it completely except for the hotend temp…it tops out, shuts down for a second, then repeats.
S3D, nor any other host software is sending a command to do this, no command to set a hotend temp has any effect.
Even when no printer software host is running it does this.
But wait, it gets better.
This happens even when the computer is turned off.
There’s more.
This happens even when the computer is unplugged.
This happens even when the USB header is disconnected and the PSU to the computer is disconnected.
Now,
It does NOT do this when I connect it to a netbook.
I thought it may be a ground issue, since the charger on the netbook and the computer and the printer are not on the same outlet.
But the outlets all check good with a GFI tester and switching which outlet plugs to which changes nothing.
So, since it does not do this with the netbook, and I can print from an SD card with no issues, I figure it’s gotta be the computer.
The problem is, I really want to restore the ability to print and work via the USB on my primary computer.
I have not altered the firmware of the printer in any way, and no other peripheral on my computer is effected.
I have even replaced the motherboard on the printer with the otherwise correct wanhao motherboard…no solution.
Does someone, anyone, have any ideas or suggestions?
Try a different USB cable or a different header on the motherboard. Make sure headers, ports and plugs are all clean and free of dirt. You can also get a cheap PCI USB Hub and try that.
It sounds like there is a short being created somewhere. Though since u mentioned having the header and PSU disconnected but still getting the issue, the short may be in the port itself. Try using another port or cleaning the one u are currently using.
You could also buy a small cheap USB port tester which will test the USB port for ground as well as tell you the voltage and current it is running so you can check if it is functioning correctly.
Also try re-installing ur USB drivers and or even re-flash the firmware on your printer.
Good luck
Rate8x
3
Thanks very much.
I’ve tried different headers and cables, no joy.
The PCI USB hub is a great idea.
Free of dirt…I did do some drywall patch in the room an it’s dusty…but I guessed since no other system is effected…
Port tester…Thanks again, I’ll try that.
I did look to see if any driver updates were logged, then I updated the drivers. No joy.
I am very hesitant to reflash, bought a replacement board just to avoid it. I’ve never done it, I have what I need if I had to, but I worry about turning a sick printer into a dead one.
I appreciate your suggestions!
Rate8x
5
Yes, I’ve tried each of all 10 USB ports on the machine. 8 are USB 2.0, 2 are USB 3.0 (just to see)
I will try a PCI card, I will get a tester. Thank you for those suggestions. I was not aware of USB testing devices.
I’m beginning to think that there’s a ground, ground loop or a float (where they are not supposed to be) between the printer and the PC. A problem not presented with the netbook…so it could still be the printer. I’m not really skilled with electronics, so if that sounds crazy…it could just be my ignorance and not my insanity. I’m also wondering if the PSU on the PC is getting to that age.
Thank you again.
Did you use the same USB cable on both the computer that it’s not working on and the laptop that it is working on?
If there was a ground or float issue it would be highly unlikely that it would be present on multiple headers. An issue with your PSU could cause issues across all headers but you would likely see problems with other USB devices also not just the printer.
Hmmmmmm… after re-reading your original post. I assume that if you plug the USB into the printer and DONT plug the other end into your computer, it doesn’t have this issue, it’s only once you plug it into the machine?
Have you change anything in your computers configuration recently (Both hardware/software related?)
I’m wondering if you have a BIOS setting that has enabled the USB ports to be “Powered” even when off (This is generally for charging devices whilst off and allowing devices to power up the machine e.g mouse clicks / keyboard presses). If this is the case, the output power capability of the port could possibly be causing an issue as the 3D printer might be getting a power signal and miss reading it as an instruction to heatup the hotend.
Rate8x
7
No, two different cables on all PC ports. Either cable works w/ netbook.
If not the PC PSU, the Printer’s maybe?
Correct, USB into printer and nothing else does not trigger the problem. USB to netbook does not trigger the problem. Only USB to PC…even a completely disconnected and unplugged PC.
No changes to the PC I would flag. No new software, not even windows updates. I’ve done all the drivers hoping to clear this up…but that’s about it. My Wacom tablet wants updates every week or so, I can’t imagine why that would change the PC’s circuitry when unpowered.
My PC has a P6X58D-E mobo running default BIOS. It only gives me: Enable/Disable controller, Full/High Speed and E/D legacy options. I have not messed with these.
It occurred to me that a setting might appear to be a command, but if that were the case, I could simply send a command to turn off or go to a lower temp…no command appears in the log, no set temp is reported when the host software is running. Like I said, it even does this when the PC and USB headers are unplugged and disconnected from the mains.
I know, it’s a doozy.
Hmmmm, very strange. The only other possibility i can think of is a shortbetween the ports/hubs and the actual computer case then. I don’t believe it would be an issue with the printers hardware due to it working fine on the netbook. The only way i could see it being a printer issue is via software. But then i wouldn’t think it is capable of telling any difference between machines.
Are the baudrates on both the laptop and netbook the same?
Also, does the hotend start heating up before an active connection is actually established with software?
Rate8x
9
That is a possibility, I’ll try to figure out how to check that. I know how to use a multimeter, just gonna have to figure out where.
I’m pretty sure it isn’t software. I use S3D on the PC, Cura when checking the netbook, Cura on the PC but having repeated the problem with no software running and no power (PC not running)…I think some kind of bad connection is more likely.
Baud rates have always worked at 11520.
Yes, just plugging it into the PC with no software and even no power does it. I tested the outlets for ground, they test good.
Rate8x
10
So I have continuity between the PC case and the USB shield on the ports, all of them…should I have continuity?
No, i was just about to suggest a continuity test between the port and the case.
That is your short and almost definitely your issue. “Easiest” way to test would be to take out a hub so it’s not mounted in the case and see if the problem is still there.
1 possible place for this short is the motherboard stand offs. if there is 1 close to the USB header (Or for that matter, anywhere within the headers track paths) it is possible that it is touching a contact or that a tracks coating has become damaged and the bare track is bridging through the stand off.
Could also be dirt/lose screw/anything that can carry a charge caught behind the motherboard bridging a USB related contact to the case.
Best suggestion: Take the motherboard out completely, clean the entire board and the case check for any wear around where the stand offs sit behind the motherboard to make sure they aren’t making contact with anything that could cause a short.
Whenever i install a motherboard i always put a non-conductive rubber/nylon washer/gasket between the stand offs and the motherboard.
Hope you get this fixed. I hate removing motherboards, always a pain 
Rate8x
12
So just to be clear, I should NOT have continuity between the port’s shield and the case?
Thanks, I’m sorry to ask…I’m just a bit out of my depth.
Even if it isn’t the root of this problem, I probably oughta fix that anyway!
Just done some googling on the subject as i thought aout it and questioned myself and am now uncertain.
If it’s between the USB ports shielding and the case then im thinking maybe it SHOULD have continuity, since a computer case acts as earth. If however you test all the pinks in a port separately and more than 1 pin has continuity with the case then i would think this is wrong. And even if only 1 had continuity i would still be uncertain as im not even sure if a USB port has a ground other than the ports metal shielding.
Try and test the pins, if they all have continuity then it is definitely wrong.
you can make it easier to access the pins by attaching a USB cable to the port and then just test the plug on the other end of the cable.
Found this. The only one i would say that is ok to have continuity with the case is the GND. If any of the other pins have continuity then i would try it outside of the case and see if the printer then functions correctly.
Rate8x
16
I have taked the PC down, dusted it and tidied up some routing.
The USB port shield no longer connects to the case. It does ground to the PSU…I think the components are isolated from the case. They are now at least.
The Shield connects to the ground pin, which is a black lead where I stripped off a test cable. None of the others; red, green white…connects to the shield or case.
I checked to see if anything was solved. Not yet.
One thing I checked just recently…
I plugged the USB cable into the Printer and touched the shield of the cable to the shield of the port.
When the PC is off, nothing happens…improvement. It used to kick on the hotend.
When the PC is on, problem repeats.
I hate to take up all your time. I’ll get a PCI USB card and a port tester and see if that tells me anything and check back.
Not at all, i do tech support as a hobby as i have nothing better to do. First time doing 3D printer tech support though xD This is a very interesting issue and i am happy to try and help as i also learn form the experience 
If it’s now all clean though and the stand offs aren’t shorting anything to the case then i am actually qwite perplexed myself at this point. If you have an old spare PSU it may be worth just plugging in enough to power up the board and see if the issue still persists. Otherwise yes, try the PCI.
Note: there are much cheaper PCI cards out there with less ports on but i sent that one since it as actually more useful to use after solving this issue
Rate8x
18
I might know someone who’ll have a couple lying around.
I just can’t figure out what I could have done to cause this and how to undo it!!!
When I gather some more tools, I will update you.
Thank you so much again.
Might not have done anything. Components degrade over time which can make strange things happen seemingly out of nowhere.
Good luck, hope u get it fixed, look forward to hearing your results
Sounds like you have run a number of different scenarios with only the printer being the common item.
That would leave me to believe that the issue is in the printer. I think it is safe to say you have eliminated the PC as a problem.
Have you done a reset of the printer back to its factory defaults?
Have you done anything to the printer? Check for any wires related to the hot end that may be grounding out.
