Hello. System E1234 error is indicative of memory riser power failure that may be caused by either the DIMM(s) on the riser or the raise itself. The first thing you do is to power down the server and reseat the riser and associated DIMMs. However, it is also possible that it could be a system board issue. Have you done any troubleshooting to truck down the source of the error?   Just replacing the system board may not solve the problem. You might consider swapping the riser and when the error follows the riser; swap the DIMMs as well. This will point you to replacing either the riser or DIMM(s). But when the errors stays in the same riser position, then it could be a system board issue.
Hi  we are using 2,  R910 poweredge rack servers, but eventually.... one of them stopped working, when our techinical team checked the server. but server does not powered on ... no display but giving the error E1234 Riser A error ..., when we replaced the other  server board and riser it doesnot work ... then we placed the board to the actuall server 1 it also stopped working .... what should we do ... plz reply ....:)  
Poweredge R910 riser error E1234