Sorry guys ; dont have the exact model number but it is the same as this Mac I recently after 10 years with no problems ; had a KERNAL panic [ second last time I turned on the computer ], 2 Lockups on the desktop where nothing would move, One instance where I turned the Mac on, and the lights on the front were flashing, and just and overall sluggishness. Initially I was concerned with the HARD DRIVE, so I backed up all my files, but some of the files were corrupted because of a bad transfer [ Assuming this was something to do with the Ram ] The computer will start most of the time, with these having happened over a 3 week period. Sometimes It would run fine, and other times, the above happened. I have a couple questions, I found some sticks of 4GB OWC for a good price and they are on there way here. But I wanted to do a couple test. I am assuming [ LARGE ASSUMPTION ] that it is just a bad stick of RAM, and or worse case, that there is something wrong with one of the RISERS, as when I checked the hardware, It only said I had 1 stick of Ram in there. So onto my questions, If it is a faulty RISER slot, we'll just say DIMM 1, Can I place my new ram in DIMM 2 on both sides, and the computer would run fine? If not ; what are my options. How do I determine which way to insert ram into the riser, Is there a simple "front / back" marker on them. Also I may have mixed up which RISER was A and which was B.. Does it make a difference which one goes into which slot? If so how can I tell the difference... I'd be interested in other theories as to what could be happening! But I am hoping its just a bad stick of ram. I can provide more info if requested. Thank you very much.