Duo RX on speed

[Slypty]

Having an issue with my RX, can't get the laser to stop spinning wildly.  Usually it won't read CDs, but when it does it whirs way too fast.  I know about the POT to adjust and change, but that did nothing.  Here's the symptoms:

-  With a good laser, games will spin quickly right away.. no stopping to check the disc, just straight to whizzing too fast.
-  When I use a good laser, and put it back in to my Duo (not the RX)< the laser loses its calibration and needs small adjustments.
- Tried replacing all pots, changing laser assembly, nada
- This system was previously Region modded (attempted but failed.)  When I got it, I had to replace the cut Hu card, and the owner fried the 6260 when attempting the mod.  I replaced the chip and fixed that, now I'm left with this weird error.  Wondering what other chip errors may cause this?