Geeetech

This is my first 3D printer. I have had my A20T for about two weeks. It printed about 5 files as perfect as they were designed. Then it started messing up the top with holes and the back with holes and artifacts. You can see all the way through from top to side. I have read several troubleshooting guides on the internet, none are for the A20T, but I feel they will be true for all printers. Trouble is none describe my problem. I have leveled the table at least 6 times, changed temp from 200 to 215 C and between. On leveling the table, I read to do it wright, you need to have the tip and table hot. I have done that hot and cold. I am trying to learn how to use the printer, but have limited sources. Any help would be appreciated.

Well, after doing a lot of reading and printing a lot of test cubes, I solved my problem. Apparently my problem was that the temperature was the cause. I was not printing hot enough. Being new, less than a month with the printer, I had bought more petg filament than PLA. I was using the petg just at the bottom of its operating temperature and had read or watched a video that the PLA did not need to be as high. I also found there is a lot of false information available. I do not have a connection with anyone to get advise from. For me all trial and error.