First how are you connecting to the printer? Is it a direct USB connectionor are you using a USB hub or print server (sometimes part of a router)? If a USB hub is in use, is it a USB powered hub or a self-powered hub (AC adapter)? (Make sure that the printer has power and is turned on. Also make sure that you have printed and scanned a calibration )
If you are not using a direct connection, try a direct USB connection. Use a different USB cable and try different ports (some ports have lower power throughput than others). Make sure that you have the correct driver for your OS. (The full software is useful for other issues.) See http://www.epson.com.ph/epson_philippines/printers_and_all_in_ones/inkjet/product.page?product_name=Epson_Stylus_TX121
for the drivers.
Try uninstalling the current printer driver and then disconnect your data cable (USB). For Windows, press Start and open the Devices and Hardware control panel (Printers and Faxes in XP) from the right hand column. Right click on the printer and select Uninstall (or left click and choose Uninstall from the Menu bar). Reboot the computer and install the Epson printer driver before reconnecting the USB cable. (Otherwise you can get the OS driver that may not work as well.) Remove your data cable from both the computer and the printer and turn off both devices. Unplug the power cord from the printer and the wall outlet. Wait a few minutes before reconnecting the power. (This will reset most printers if there is an error in the printer itself.)
If you are using a print server and the direct connection worked, check the installation information for using the print server. Not all printers are compatible with certain print server drivers and you can have a conflict.
If a direct connection to any of your computer's USB ports does not work, check if other USB devices work. If not, try updating or uninstalling your USB controller (in the Device Manager for Windows - Start > Control Panel > System and Security > Device Manager, scroll down to the Univeral Serial Bus controllers). Then reboot your machine and see if the correct driver installs. Alternatively, check your computer manufacturer and see if there is an update for your USB driver.)
If the problems persist, you may have a bad USB port on the printer. Please add a comment with the type of connection between the computer and the printer.
I hope this helps.