Aqualinks RS4 Control Board Relays Won't Turn Off

[rkjunker]

I have an AquaLinks RS4 and the Control Board (the one outside in the Power Center) does not seem to be working. The relay plugs (the two-wire plugs on the bottom of the board that go to the relays and control motors and lights) on the control board are pushing out 32V on all lines but the Filter Pump connector, which is keeping the relays on and not allowing the Booster Pump and two lights to work properly. They just stay on permanently. I am having to turn off the breaker or unplug the two-wire connector to keep them off. I’ve confirmed that the actual relays work as they cycle on an off when unplugging and plugging in each connector (I hear them click).

In Service Mode, I will be monitoring the plug voltage and it will read 32V and then I push one of the AUX buttons to turn OFF/ON and the voltage does not change. When I do this with the Filter Pump button, the voltage is 0V when it is OFF and goes to 24-32V when I turn it ON.

In the Troubleshooting Manual, it talks about Driver Chips that control this voltage. Why would only 1 out or 4 of these be working? Are they connected, or is there a Driver Chip connected to each AUX socket. From my research on the Driver Chip (ULN2803A), this controls Filter Pump and AUX 1-3. So could this be a bad Driver Chip, and is this replaceable? How could I determine if this would even solve the problem.

What can I do? I tried a reset on the Control Board and that didn’t do anything. I'm also concerned that there is 32V at each of these plugs, where it seems that it should be 24-28V.

I called Zodiac and they said to buy the new replacement Control Board.

This is my first post, thanks for any feedback.

 

[OldPoolMan]

Hi RK, and welcome! Leaving aside the voltage issues, it is fairly simple to determine what's what in the RS controller. The best way to determine whether the relays are good is to find the one relay plug that works and one by one plug each of the relays tnto that socket and try them. They are all the same. If one relay works in a plug then they all should unless they are bad. If two or more don't work, it's probably the board.

 

[rkjunker]

Thanks for the reply. The relays are definitely good, I checked them with the one good socket and they all function properly when wired to the Filter Pump socket. I definitely think it is the board at this point, I am going to see if I can replace the Driver Chip and see if that makes a difference. I just need a good source for a ULN2803A.

Unless, someone else has a better idea, I'm going to try that.