Hayward Aqua PLUS Control Panel power cycling

Grayrock

New member
Jan 1, 2025
1
Virginia
Hello group, now that my pool is closed for the season, it's a good time to troubleshoot my control panel. One day it will work fine, sometime a whole week, other days it will start power cycling like the breaker is tripping, (not the case) before I fire the parts cannon at it, what area should I start troubleshooting? I can definitely fix it once I know what to replace, even if it's at the component level. Yes it does have the salt water cell, unplugged in this picture. Thanks! IMG_4436.JPG
 

U4/U5 Relay Driver Failure.​

The U4 and U5 chips are Micrel MIC5841/5842 relay drivers[5] that control the K1, K2, K3, actuator and power relays.[6]

A relay failure can blow out the driver chip. If you replace them, you might want to test continuity on the relays to make sure they are not shorted.

Hayward Aqualogic U4 Driver Failure.jpg
When a member replaced the U4/U5 chips he added sockets so they could be easily replaced again.[7]

Parts used were:

 
 
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How did you solve your issue? I appear to have the same issue. Display comes on for a few seconds then starts cycling, becoming shorter each time.

So far I've traced the 24v AC from the red/black leads. The order leads exit the board (assume it should be 24v AC into the rectifier (converts ac to DC). I'm getting no voltage from the orange leads which according to hayward makes no sense. I asked AI and it said the transformer can test good under no load but fail under load. Going home tonight to test the rectifiers but I suspect its a transformer although the resistance on the transformer is nominal.