Hayward GLX-PCB-MAIN blowing 3A fuse

[Aeden71]

Morning all,
New the forums but in need of some assistance.

I have the above-mentioned board, Hayward GLX-PCB-MAIN (PN: g1-066008n-1) and the 3A fuse is blown.
I purchased another 3A fuse, made sure power was off at house breaker, replaced the fuse and turned on the power.
Immediately blew the 3A fuse again.

Everything I find online talks about the 20A fuse as if there are no other fuses. The 20A fuse is fine.

This is a replacement board that has been running flawlessly for two years.
Inspecting the original board I found the same 3A fuse blown.

I am no electrician, but instantly blowing fuses implies a short circuit but I do not see any.
Nor do I see any burn marks.

Has anyone run into problems with the 3A fuse found under the control panel?
If so, what should I check to correct the problem?

Thank you in advance.

 

[JamesW]

AquaLogic main boards have a 3amp violet ATO style fuse that protects the local display circuit.

It might be a bad display.

With power OFF, disconnect display, replace fuse and restore power. Verify, across pins 1 & 3 (left to right) for 5-11VDC.

http://haywarddocs.info/wp-content/uploads/2017/10/2016-ProLogic-Troubble-Shooting-Guide.pdf

 

[Aeden71]

James,
Thank you for the response.
I did as you suggested and as soon as I restored power, the 3A fuse, immediately, blew again.
Without the display connected.

Any other suggestions or ideas?

Again, thank you

 

[JamesW]

What is the model number of the box?

Do you have a picture of the board?

 

[Aeden71]

Images attached.

Hope this helps.

Pulling the board off, in decent sunlight, I can see a possible scorch on the back side.
The last image, "Possible Scorch" is a pic of the back side (upper left image) and the front side (lower right image)
The red circles indicate the position of the scorch mark, on front and back.

At this point, I assume I'm buying yet ANOTHER board.
This is a replacement and only a few years old.

Thank you,

 

[JamesW]

Do you have 120 volts powering the control board?

 

[Aeden71]

Yes 120V
This board has been running for a couple years and nothing has changed.

 

[JamesW]

If you have anything connected to the Remote Display, try disconnecting it to see if that makes a difference.

Measure the voltage going to the board to make sure that it's correct.

 

[Aeden71]

I did as instructed, 120V going to the board.

 

[JamesW]

Other than replacing the board, I don't know what else to do.

 

[Aeden71]

James,

Thank you so much for all your time and suggestions.

I'll be replacing the board.

 

[JamesW]

Overall, I don't think that it's a common problem. Since you have had the same issue with two boards, I would suspect that there might be something specific to your system that's causing the problem, but I don't know what it could be. Maybe get a surge protector for your electric components.

Maybe it's a bad display that's shorting out the board?