Q:

Recover data from IBM x3650 with SYS BRD ERR

As in every sysadmin nightmare after shutting down a server I'm not able to power it on any more.  The server is an old IBM x3650 M4, which has been shut down because unused and of course when not available users recalled they had something left there. 
As said the serve won't boot, I tried replacing the CR2302 battery, letting it off without it for several minutes but nothing changed.  I need to recover data from the RAID, more than an answer I'd like to get some ideas about the options I have. 
The disks are connected to the mainboard to the SAS0 and SAS1 ports, the RAID controller is attached to it. 
I've a spare x3500 M4 tower server I could use, but it uses 3.5" SATA disks I guess the controller is incompatible with the disks. 
Is there any other option than replacing the mainboard? 

A:

As @mforsetti suggested I found a similar server, put the disk in place. 
When the server started and detected all the original disks were gone it suggested me to open the LSI config utility.  It detected a Foreign configuration.  I loaded all the configs available (even if only one), changed boot config and the OS started without problems.