did you try unplugging and plugging back in the power supply, also try rebooting computer, I know it sounds stupid but some times I have to do that when for some reason the USB ports get confused.
Yes I did. In fact, that’s the first thing I did. Still running through everyone’s comments seeing if anything will work, unfortunetley… Nope 
roko11
10
Hi, well at least something is happening. Let’s try something.
I tried to replicate your problem with Repetier Host
I disconnected my printer (Com9) from the computer USB cable unplugged.
I had previously had it connected to RH.
I tried to connect without doing anything other than disconnecting the printer. I got a small wiindow that said “The connection failed Com 9 does not exist. do you want me to open printer settings etc.”
I went to Config - Printer-connection-port and the choices were AUTO and Com1.
I plugged my printer in and reopened port and there was AUTO Com1 and Com9.
I selected Com9 as the port. Closed the window and hit the connect icon and it connected.
I really don’t know what else to tell you other than make sure that the Arduino program is not open and connected when you try that.
Also the only time I have seen "access denied Com(port number) was in the Arduino program itself when RH was already connected to the board…
Well repetiers has no problem finding my com3 I just don’t have access to it. Also whenever I reflashed my arduino, everytime I tried put Marlin back into it, it won’t let me load the whole file. It says “com3 is busy or in use” even though I just reflashed it. So its almost like somethings on it and it won’t let me connect my printer to it. Been researching all day, still no luck.
roko11
12
So are you saying that you tried what I suggested and the result was like mine?
Also the fact that you can’t get it loaded all the way using arduino could have some bearing on that problem if it is an incomplete load to the Arduino board.
I have sucessfully flashed mine with version 1.6.5-r2 but other people have had to use an older version of the Arduinoi program.
Unfortunetley no. It still says com3 is in used and can’t be accessed. I closed everything down including arduino and retried it. Still same message that it’s busy. I’m going to try a new flash and see if that helps. Maybe some older ones. Let me ask you, besides marlin, is there anything else loaded to your board?
Everytime i try to load something new into my arduino, heres what it says.
"avrdude: ser_open() : can’t open device "\\.\ Access is denied.
“avrdude: ser_drain() : read error: The handle is invalid.”
So now its like i cant even reflash it. Because anytime i try to load something new onto it, this is the message i get.
Try installing Matter Control and see if you have the same problems: http://www.mattercontrol.com/
I tried to set it up, and it says unable to connect. When i look at the tab, it says, “Com3 in use” What the heck is using my com 3?
Hi, you’re not telling us enough, so there are 1,000,000 possibilities for what could be the problem(s).
- exactly which brand or vendor is your Kossel from?
- what hardware are you using? Ramps, Sangoluino, Rambo, etc.
- what firmware are you using?
- what software are you using on the computer that is connected to the printer?
- what operating system is on the computer? (If it’s Windows 10, or iOS, then I can’t help you)
- what does it say on the LCD ?
- when you say you’ve “cleared my arduino” what exactly did you do? When I do that I have to be connected to a comm port, but you say you can’t connect, so I see contradictory reports.
Again, provide more detail. Once you narrow things down someone here may be able to help you. It will also allow you to create a narrower search for Google and you may find answers that fit your situation. Everything I’ve learned about 3D printing came from careful Google searches. It’s always a flurry of confusion at first. You just have to dig in and learn. It will clear up with some effort.
2 Likes
if you are using win 10 update windows as earlier versions had big problems with usb connection for printers. drove me nuts for 3 days until i restarted my pc and it updated
Yes, this, a million times, this!!!
I’m having the very same problems as the OP, but I have not even gotten an initial flash to work. The printer is just a paperweight at the moment. I’m running Windows 10, and I’ve tried Marlin and Repetier, ensured only the one instance of Arduino is running and RH is disconnected, but I still get the same errors:
"avrdude: ser_open() : can’t open device "\\.\ Access is denied.
“avrdude: ser_drain() : read error: The handle is invalid.”
My LCD is still just showing two lines of blocks. I am not discounting that I might have some wiring wrong, too, as it is a board I cannot even find online. It is not the board the chinese instructions showed me, and I took my most educated guess at the configuration. The board states it is an MKS Base v1.4. I am only on my second day of research, but I am hoping to figure a solution soon to just get the thing in motion so I can start the fine-tuning. I am going to attempt to download and try an older verison of Arduino next to see what happens.
The main CPU looks like an atmel 2560. Basically a RAMPS setup. If you want help over Skype and phone let me know. I sell tech support for open source Printers. $15 an hr but send me email directly or donation to my YouTube channel and I will help you out with your problem. Arduino 1.0.1 Open tools tab and select your comport, set programer to Arduino as ISP, and set board to mega or mega adk. Then try again. You will have to set the correct board in the firmware. george@georges3dprinters. com
Sounds like you might not have the driver installed. Check device manager for something like arduino or USB to serial device or something Good luck
Thanks, George. I reset everything and uninstalled RH, and reinstalled Arduino 1.0.6. The firmware seemed to update fine, but my LCD is still just a bunch of blocks. Repetier Host is recognizing the printer, however. Unfortunately, nothing appears functional. Could be a wiring issue. I will keep at it.
I had that thought, but I tried installing the driver that came with Arduino several times. COM3 appears when I connect the driver, though the name of the printer is never stated. Just says COM3.
You could try swapping the LCD connectors. Did you uncomment the right LCD in configuration.h?
Delete the two slashes in front of the line for reprap smart controller. In configuration.h
1.0.1-1.0.4 is usually recommend. Reason why is that library changed for LCD
