I've got a Jtagged Falcon that will boot up fine but if i go to turn it off and on again i will get e79, I would have to wait a couple of minutes before turning it back on and then it would boot as normal, it seems a fair few people are in the same boat.....

Over on xboxscene Bukmop has come up with a solution.
I did a bit of a search and couldnt see that it had been posted before so thought i would post here as it has worked for me

BTW
Some people had to reflash there kv and config files but it worked just by replacing the resistor for me.....

We all remember the diagram for Jtag Hack very well. I mean there are 2 diodes and 1 wire (as jumper).
Few days ago I needed to get the CPU key using Xell loader. My MB version is Falcon. At first I've read the original NAND successfully. Then I've prepared falcon_hack.bin for flashing. After successful flashing procedure I've soldered 2 diodes and 1 wire following diagram. When I've powered on my Xbox I saw 3 RRoD. I was confused. Several reflashing procedures didnt solved my problem. Every time when I've powered on my console 3 RRoD appeared.
In that moment I've recalled about early version of diagram for Jtag Hack. I mean 330 Ohm resistors. And I've decided to use one 330 Ohm resistor instead wire (between J2D2.4 and J2D2.7). Finally it fully solved my problem. And 3 RRoD are no more. With that resistor everytime I've got the successful booting of Xell loader. I think this information will be useful for our forum members.