Need Help; U14 Function in AquaTrol? Made Modification

[SCobra1]

My first post here......
My older AquaTrol display board went out completely. I found information in this forum that helped me t-shoot the problem down to a missing 5v. I also found a basic schematic that indicated U13 was the 5v regulator and U14 was in the supply circuit as well. U13 was working perfectly but U14 was not turning on. I’m not really sure what U14’s function is????

I jumped the good 5v around U14 and all is well now. Does anyone think this is a problem?

Anyway, thanks again to all of the contributors!!!

 

[Texas Splash]

Welcome to TFP! I'm going to modify your thread title since I think it may be throwing viewers off the scent. I'll include your configuration issue in hopes you get more hits. Have a nice weekend.

 

[C0d3Sp4c3]

I jumped the good 5v around U14 and all is well now. Does anyone think this is a problem?

Chances are, the EEPROM data might get corrupted and render your mainboard useless. The U13 chip is NOT a Regulator but a 4.0V Reset Monitor. The U13 & U14 Datasheets are available over the internet should you wish to expand your knowledge.
The U13 & U14 are protecting the Microcontrollers from voltage sags or in the event the 5 Vdc supply drop down below the min threshold of 4.0 volts. Most likely to happen immediately after disconnecting the AC power to the system and the caps are discharging.
By design, when 5 volts is applied to a failed U13, the Vout will pull down the "CTRL" pin of the U14 to the Negative going, thereby turning off the 5 volts output. You can however, remove the U13 or break the circuit trace connecting the U13 Vout pin to the CTRL pin of U14. Power on the pcb, if the LED's and display works then you know U13 is bad. But then again, by doing so you are at risk of losing EEPROM data.


The below videos might help
Aquarite No Display No Lights == Fixed ==

Hayward Aquarite and Aquatrol/ Display and LED's not working/ Diagnose and Repair

 

[SCobra1]

Thanks for detailed explanation and the videos. I guess I will be replacing U13. Thanks