I bought four S1's a month ago and had a similar problem. The good news is that it wasn't too difficult to fix! I ran my four units over night and checked them in the morning only to find multiple x's on my asic chips and the one unit was running at around 100 gh/s. I did a little research and downloaded the latest .bin file from bitmain which you can install/flash to each S1. It said that this new version eliminated false asic chip errors and guess what... It actually solved my problems! I went from xxxxxxox ooxxxoxxo xoxoxoxox to all 00000000 in my asic chip status. Only one unit got an x again and it went away and stayed "o" after a reboot. Reflashing a new .bin file wasn't that difficult to do so here are the steps.
1) Download the latest .bin file (antMiner_openwrt20140207.bin) and save it to your computer. I made a folder called "mining" to keep the new and backed up files in it. You can find the .bin file here:
https://www.bitmaintech.com/support.htm?pid=00720140411033846942qQqjOD4606952) Log into the antminer interface by typing the IP address into a web browser.
Mine is 192.168.1.201 ... Username root, password root.
3) Click on the System tab, then click on the Backup / Flash Firmware tab.
4) Make a backup of the current configuration file by clicking 'generate archive', and save it to your mining folder. (Just in case you need to revert to your old settings)
I used 'save as' so I could name the first backup with a 201 at the end for my unit that ends in .201
5) Now install the new .bin file by clicking the browse button under the 'flash new firmware image' section. Locate the file downloaded in step one (antMiner_openwrt20140207.bin) and select it. Click the 'flash image' button directly to the right of browse. It will take a few seconds (mine took 15-20) to upload and a new page should appear that verified your new image. Click proceed and you're on your way.
6) Repeat this process for each of your units. Run them for a day and report back to us to see if your problems were solved.
This solved all my asic chip problems. I check each unit every couple days to make sure that they are all 00000000 00000000 00000000 0000000. I got an occasional x0000000, but it went away after a reboot. Feel free to tip if this solves your problem or if you find this useful. BTC Address: 1HyBKPMAQKag3vGyHaa9TwkEzu5CCFWXAC
Here is a link to another one of my posts that describes my S1's problems.
https://bitcointalksearch.org/topic/antminer-s1-hashrate-and-hw-errors-579769Let me know if this helped! I spent a lot of time troubleshooting and doing research to fix these problems!