Hi Mohammed,
I've never seen a logiq A5, but I have seen a logiq P5 and as far as I know they are similiar. Also, I dont have much experience with the logiq P5, but from general ultrasound system troubleshooting, it sounds like a back end issue. Since you have already reloaded software for the system we can eliminate that.
I was trying to look for an A5 service manual on the GE Support Document, but it doesn't look like they have one. They do have a P5 manual, u can find it at the GE website here http://apps.gehealthcare.com/servlet/ClientServlet?REQ=RNEW&MODALITY=US.
From a quick look at the manual it looks like you may have a bad SYSCONCM. Thats the main backend processor board, pretty much the computer that runs the back end.
Try that, and if you would like any more help you can contact Conquest Imaging at 866-900-9404