You can find the Jandy AquaPure manuals, here
I'd recommend you walk through the troubleshooting guide the manuals and learn the terms used there.
If you don't solve the problem, call Zodiac customer service at 800-822-7933, and try to get through to their level 2 techs. You're more likely to succeed IF you've gone through them manual, since the level 1 techs will mostly just try to walk you through that over the phone. When they start doing so, you want to be able to say -- using the right terminology -- "Yea, I did that. And, that. That, too, etc."
You probably also want to follow any process for testing the power supply. After 3 years, you may well need a new cell, but you probably want to make sure the the power supply is OK. If it's not, you essentially will need a whole new system, and there are probably better choices than Jandy, for SWCGs.
If you DO purchase a new cell, you will maximize life by buying the largest cell that will work with that power supply. It looks like that might be the PLC1400, which lists for $919.17 in the 2011 Zodiac catalog. Currently, Amazon lists a JANDY PLC1400 Pure Link Replacement Cell Kit 1400 for about $625.