Gastrof:

You can use a "Y" connector found at any Radio Shack or computer store to split the power off of the DVD power source if you cannot easily modify the power acess to the existing fan.

Don't assume that the jerkiness is necessarily heat related. Various potential sources of "jerkiness" have been reported in the forum. But we know for certain, that Liteon added heatsinks to the three major chips after a certain manufacturing date. We also know that many have modified their machines to improve ventilation/cooling. My point here is, you can do all of the right things and still get "jerkiness". It could be "dropped frames" in the data stream, poor media, some minute variation to the laser during the burn, etc, etc, etc.

But, good troubleshooting starts with eliminating the obvious simple problems first. That's why every manual starts out with "If the unit does not turn on, check the power source". This is the same thing. Eliminate heat as a possible cause and then you either solve the problem or move on to the next scenario. I just don't want you to assume that we "know" your problem is heat related.