Hi. Sorry. Been busy with the holidays.
OK, so you've got the Power Center. That's the box with the big transformer in it. You've also got the beginnings of the burned connector Matt was referring to.
Usually, when that connector burns up, the IntelliChlor (IC) stops working altogether. So it may be that, or it may be the bus (the wires and connectors and circuits that do the communicating). That's the green and white wires. The red and black wires carry the power for the IntellipH (IpH) and the IC.
So before you go replacing anything expensive, I would do the following.
Take apart any connectors that have the red, black, green and white wires. Scratch, sand, scrub as best you can any metal inside the connector. Clean the pins, both male and female. Blow out your "scratchings." Then apply some dielectric grease (
like this stuff) to all the pins to protect the connectors and inhibit future corrosion. This includes the black twist connectors on the outside of the IpH and the Power Center.
Do the same anywhere you can see the four wires (red, black, green and white) going into terminals. In your Power Center, I see a cable with two wires, red and white. That is not usual, and I can't explain what I'm seeing, but clean and grease those, too.
Then you need to do the IpH connector "fix." It's going to require some soldering. You can use wire nuts or Wago for the big wires (grease those connections, too), but you'll need to solder two jumpers to their respective pins. This all happens inside the IpH. Other than cleaning the pins of the green and white wires inside this connector, you DO NOT join the greens and the whites together before the connector as you do the reds and the blacks. Like this:
Taken from this post, which you might want to review.
If you really want to have some fun add a couple of sensors to that thing. Then you don't even have to break out the test kit. Did you write up on the forum somewhere how to accomplish that? I'd like to read about it.
www.troublefreepool.com
If you have any questions, shout 'em out.
IMPORTANT: this "fix" will void your warranty. I'm assuming your IpH and Power Center are out of warranty. If not, then call Pentair and let them deal with this before you do anything else.