I had a mistake in the bitcointalk forum version of this guide.
The mistake was in the Table 1. AvalonMiner LED colors.
There was an image of PMU LED colors table, which is obviously a wrong image.
I have put the right image in place now.
It took me too long to notice the error, sorry.
The .pdf document version has been ok the whole time.
BTW. Steven has posted a neat promotional video for the AvalonMiner 851 at the Canaan.io website.
The video also mentions the easy DIY repairs, which this guide supports.
Direct link to the video:
https://youtu.be/pJmJ4nFOiig