SQL to LINQ unable to convert SQL join query with multiple conditions with "and"

See How to do joins in LINQ on multiple fields in single join.

You cannot use the && operator to select multiple columns in a Linq method syntax join. Instead you need to code your outer and inner key selectors to each return both key values together in a new anonymous object.

In your case, something like:

    .Join(xAMControlX4Context.X4AlarmConfigs,
          ppc2 => new { ppc2.ppc.j.InstanceID, ppc2.ppc.j.PropertyID },
          a => new { a.X4Instance_ID, a.X4Property_ID },
          (ppc2, a) => new { ppc2, a })

In Linq To SQL, thinking you have proper relations at database level, you seldom need joins. Instead you use navigational properties. In your case, it is not clear if those relations are 1-to-1, 1-to-many, many-to-1 or many-to-many. It would matter just for getting the Remarkpath, Remark like properties. Looking from your SQL, as it stands, we have to consider that they may lead to multiple rows, thus it translates to LinqToSQL as:

var finalAlarm = from j in xAMRuntimeX4Context.X4Journals
                 from i in j.X4InstanceRemarks.Where(x => x.Langauge == "iv")
                 from p in j.AutomationControlPropertyRemarks.Where(x => x.Langauge == "iv")
                 from a in j.X4AlarmConfigs
                 from g in a.X4AlarmGroups
                 select new
    {
        ID = j.ID,
        AlarmAppearTime = j.OnTime,
        AlarmDisappearTime = j.OffTime,
        AlarmAckTime = j.OnNoticeTime,
        AlarmCloseTime = j.OffNoticeTime,
        AssetID = j.InstanceID,
        Asset = i.RemarkPath,
        MessageId = j.PropertyId,
        AlarmMessage = p.Remark,
        PriorityID = a.X4AlarmGroup_ID,
        PriorityGroup = g.Name
    };

Note: You can use LinqPad to write this easier. Connect to your database, and check the schema. It would show you the navigations, 1-to-many etc relations.