Here's an odd one :
I ran across an FB4 at a pawn shop, which I picked up as it is compatible with the POD 2.0 I have. (The one that just says "pedal" by the appropriate jack.)
Anyhow, I plugged it in, and it seems to function as intended: switches through patches A,B,C, and D of whichever bank the POD is set to, and the tap tempo works if I have a tempo based effect running. (the 'hold for manual mode' seems to make it so the footswitch does absolutely nothing, and I had to unplug it and plug it back in to resume use; but maybe that's what manual means) The only thing that concerns me, is that the channel LEDs are all lit all the time. I've tried a couple different CAT5 cables, and there was no change. After examining the circuit board, it does seem that the switches are on a seperate circuit from anything else in the pedal, but since I don't know how it all ties together back at the POD, I'm not sure which end the problem might be on.
The IC chips "U1" and "U2" look like they're only about 60 cents each from digikey, so I could replace those if the issue lies there... I just don't want to if they're ok.
U1 : SN74HC595N U2 : SN74HC14N