Now, if you're handy with a solder iron, it may be worth it to pull the cover off the unit and check it out, internally. it may not have any blown components, any may just either have corrosion on the pins, or have a cold solder joint.
I literally just went through this with my ng900.
I tried everything, hardware-wise, and it turned-out that it was just a couple cold joints.
I had given up on it and ended up paying someone $400 for something I could have done for free.
2008 9-5 Aero-1995 900T 'vert