I just bought new TEVO Tarantula and tried to print xyz cube. I found that my cube's layer was shifted as showed in picture. How can I fix this ?
The two most common things to check:
1) make sure your belts are properly tensioned. If there's significant slippage in the y-drive you could get the results seen.
2) Make sure the base layer is well attached to the base plate. you've got plenty of reference pattern on the plate shown, so check whether the lower chunk of print moved relative to the imprinted pattern at some point.
Do your belt goes Sproing when playing it with a finger (actually it doesn't really need to make a noise, but it should be somehow reasonable quite tight). If not, tighten the belt.
Try with lower speed, for example, it is usually hard to start off with 60mm/s or more. Try 40mm/s or 30mm/s for starters.
Up the current on your drivers! You do this by turning the potentiometer on the driver (here the X-motor driver):
To adjust the current on your stepper driver, this is a classic scheme:
With power on:
1) Turn the potentiometer on the driver counter clockwise until you can move the motor by hand.
2) Turn clockwise until you can't turn the motor by hand
3) Continue clockwise until you can turn the motor again (as soon as you feel it can't hold really hard anymore, stop).
4) Turn 1/4 of a turn (or maybe a bit less) counter clock wise.
If the current is too low, it will skip steps, especially when traveling / accelerating fast/hard.
If the current is too high, the motor will be, really, hot. A bit hot is okay, like 50°C can be considered a really safe maximum (it all depends of course, some motors can run at 80+ others could bake your electronics because it's placed badly etc.).
If this doesn't cut it, you want to check your drivers; If you can, switch X and Y driver:
If now the Y layer doesn't work, it could be the driver.
If it still breaks the X axis, your motherboard might be fried.
I also encourage you to post more information about print speeds, temperature and so on. It seems like it's a Prusa i3 clone and there are a lot of people having them and they can probably help better if this didn't cut it so please post all data available!