I am a bit confused here. Is this the standard IFU that has a CDROM that sits on top of it, and plugs into the back of the turbo grafx?
If so, I don't understand why, when you are using a 9v adapter on a unit that needs, at an absolute minimum, 10.5V (and actually expects about 13V)...and it doesn't work properly....that you wonder why.
If this IS the IFU that I believe we are talking about, the input jack is clearly marked 11V. I would change the adapter first, long before I even thought about adjusting pots.
Or, is this a different unit entirely??
Thanks for any assistance.
Charlie