I have a 506E that hangs after displaying the PCI device table. After some research I found that this can be resolved by switching the internal jumper, and having done this the device now boots successfully and loads the config.
I was hoping someone might be able to advise what this jumper is so that I have a better understanding of why this problem occurred. Secondly I came across a post which suggested that this is just a temporary fix, and that once it happens the device should be replaced. Again if anyone has experience and could comment on this I would appreciate some feedback.