Hi I'm having some problem with my 3d printer

"Marlin" is the firmware used by some 3D printers. Typically, this is flashed on an Arduino compatible chip on the printer's control board.

Could you be more detailed about:

I've read that should make change something about Marlin

Yes I can, I mean that I'm using the GCode flavor "RepRap (Marlin/Sprinter)". I read another place that somebody had the same problem as me. They fixed it by fixing/making there own GCode flavor. I just want to know if its the best/only way to go.

Can you give more details about the "motherboard"?

What markings are on the main microprocessor? 

If you are unsure, post a photo of it.

If it uses an atmel chip, chances are good its arduino compatible... which opens up quite a few options.

If you are looking to build  your own, or re-work an existing 3d printer, I highly recommend software called repetier host.

These guys write both the firmware and software.

For the firmware, you configure the options specific to your printer on their website (size, position of limit switches, etc) and it creates an arduino sketch that you can load onto an arduino mega.

Then you download their corresponding application for your pc or mac that handles all the slicing, and fires the g-code off down the usb cable to the arduino. They use the popular slicing engines like cura, slic3r, and skeinforge... you can choose which one you want to use.

Also good to know where the printer was bought and what is the original brand. Most of the cheap Chinese sellers are resellers as gearbest.

Enrico

Enrico is 100% correct, most of the cheap Chinese sellers are not manufacturers, they are simply resellers.

I buy a lot of things from Aliexpress (think chinese ebay) and they all sell exactly the same items, with the description copy and pasted from somewhere else.

Its hard to know whats going on over there, but there is probably 1 manufacturer for every 1000 sellers.

In any case the one part that works well with the Repetier firmware I mentioned is the RAMPS 1.4 shield for arduino mega.

It was developed for reprap 3d printers and since its open source, you don't need to make it yourself, just buy it from china.

Make sure you confirm with the seller if it comes with the actual stepper drivers. They are removable from the RAMPS board since people often burn them out.

Just a few thoughts...

Is there a suitable driver for the serial port on your PC?  I had an Arduino clone a few years back and I had to download a serial driver for it as the standard serial drivers wouldn't see it?

Have you got replicator G working?  Looking at replicator G it can control a Makerbot.  So maybe change the G code Flavour in Cura to makerbot and see if that gets it to connect.

If you haven't, Try Replicator G just to see if it'll spring into life... ReplicatorG is a simple, open source 3D printing program - ReplicatorG

I've included a couple of links below to CTC Printer.  Do these look anything like your machine?

http://www.ctcprinter.com/product_list.php

http://www.ctcprinter.com/product_detail.php?ProId=32

On the second link (product pages for one of the printers) it says to install Python and Replicator G

It also seems to have  a support section.

I would also suggest If you slice and put GCode on an SD card will it print? But if you don't have the g-code flavour right it'll produce odd, and I suppose potentially, disastrous results if it tries to do something it can't..

I don't have a CTC printer but this  is the sort of thing I'd do for any machine I was trying to get going.

Dan.

What is your baud rate setting? Is it 115200?

i second the above post about baud rate, i have a cheap CTC printer myself that refused to work until i changed the bad rate to 115200

If you look at a lot of the examples for driving 3D printers and other motion control solutions with an Arduino (ATMEL) controller, there almost always hard coded to 115200 baud or even higher. If in doubt then check the source code configuration files that is nearly always available.