This error is caused by a faulty/cracked RAM brick, however it can also be caused when the heatsink is shorting out a resistor or like a bad solder joint under the GPU?, check out the links in the references...
Also caused by the Southbridge if not properly soldered to motherboard or if it experiences a power short.
Can be caused by a backwards power cord or faulty power cord to dvd player.
- if you update to freeboot 9199 with bridged U6T1 or U6T2 this error will appear, unbridged it (Shadow-Wizzard)
Known Fixes:
1) Reflow the RAM and Southbridge
2) Loosen your heatsink screws and make sure the heatsink isnt shorting out a capacitor...
3) Replace the faulty RAM brick
4) X-Clamp replacement
5) Replace dvd power cord. Short in the dvd drive cord or the cord is in backwards.
6) un-bridged U6T1 or U6T2 (point that protect cpu-fuse)
You could have a cracked RAM Brick, your GPU might be making contact with some of the small resistors on the motherboard (This would apply if you maybe just did the x-clamp mod). Can you give any background as to what happened with this? Working fine one second and just all of the sudden RRoD? Or did you do something and then this started?