I have a loud hissing problem using my Rode NTG 2 when it was hooked up to my Tascam D40. When I record from the internal Tascam mics, there isn't a hiss. So I think it's my Rode mic that is causing the hiss. Has anyone dealt with this before? I've tried different input levels and always have the problem with mic. Should I get it replaced with my warranty or is this something I can fix?
It's the Phantom power. I've done a lot of testing and the Phantom power adds a lot of noise to the NTG 2. I don't know why, but if you don't run it on phantom power and use it only with batteries, the noise goes away.
As mentioned in the comments, trying a different XLR cable can make a difference here.
I also make sure that if I've got phantom power turned on (via the TASCAM), that there's no AA battery sitting inside the Rode NTG2. Sticking to just one power source has fixed similar issues for me before.
Have you applied a low pass and/or high pass filter on the audio? Mid grade mics often have built in high/low pass filtering but higher end pro mics will leave the audio feed untouched and expect you to fix it in post.