927-Non Fatal FSB Error on Front side Bus 0 ..... F7Err: Detected MCERR from Processor

[Mike1342]

My XW6400 shuts down without any warning, and I get a black screen with above error message !!!

 I then have to press F1 to reboot back.     Does anyone know what is this about!!??     Can anyone help!!???

[Mr_Raven]

This error is generally a sign of a mainboard defect but it can be caused by memory and CPU issues as well. What I'd  try:

1. Remove all memory modules except one and try again:

- If the error is gone swap modules one by one and see if it comes back (if it does then the specific memory module is defect).

- If the error didn't come back with any of the modules tested individually: remove all memory modules, clean the memory sockets with compressed air (oil free is critical!) and replace all modules (if the error is gone then it was a contact issue in one of the sockets; if the error comes back then it's a problem with either the memory controller (chipset) or the socket, so in any case it's the mainboard)

- If the error persisted with all modules tested individually move on to the next test

2a. If you run a dual CPU config: swap CPUs and check if the error goes away or changes (if it goes away: probably a contact problem with the socket; if error shows for FSB 1: CPU 0 is defective)

2b if you run a single CPU config: try to get another working XEON 50xx/51xx/53xx processor (speed/core count doesn't matter, must be known to work!) for testing and replace your existing CPU with the new one (if the error is gone then your CPU is defective, if the error persists it's the mainboard)

Hope this helps!

[Rick84]

Hi , I had this problem and i did the research ,like you do and came up with what most people did ( clean and take out ram and other things that you have added to the computer then put them back in) and this did not work ,but the Re: 927-Non Fatal FSB Error on Front side Bus 0  changed to a Re: 927-Non Fatal FSB Error on Front side Bus 1 , mmm then i realised i had not put things back in the same places . Yes it was a usb card not working . Happy days as the computers works. So try taking out all the extra cards you put in , except the graphics card and work 1 by 1 to see which 1 does not work. 

PS this is the computer that had the fault and its working great.

[Mike1342]

All XW6400 workstations have a fundamental design flaw . I experienced the same with my XW6400 for years. I have replaced many parts as suggested with many people and nothing worked. I have changed CPU , Graphic Card, Memory Modules, Mother board, and power supply, and still get a random black screen . I am convinced that the problem is more fundamental and HP knows about it.