Detailed Schematics of Hayward GLX-PCB-PRO board for transistor repair?

[mpjetta]

Does anyone know the specs of the Q2 transistor on the GLX-PCB-PRO Hayward board? Or are there any detailed schematics online for board repair that may show the values or part number?

Long story short, my Hayward system gave me the "No Cell Power 2" error a few weeks ago and my T-15 salt cell is not working. I researched it a bit (thanks to this forum) and found some brown burn marks on the back of the K6 relay and resoldered it. That didn't fix it, so I replaced the whole relay and still no luck. I've tested the relay continuity and went through the troubleshooting steps and I think my transformer and everything else is fine. The problem still seems like it is on the main board.

Upon further inspection of the board, it looks like the Q2 ?transistor? gave up the magic smoke too. Before I replace the board, I'd like to try and replace the Q2 transistor and see if that will fix the issue.

Does anyone know what the values of this SMD transistor? (I think it is a transistor) Hayward has a detailed diagram I found on their website, but the numbers are impossible for me to decipher.

Thanks!

Pictures attached.

 

[ajw22]

Welcome to TFP.

We only have what you find in Hayward Aquarite SWG - Further Reading

If you figure more out let me know and I will add it to the Wiki.

 

[generessler]

Does anyone know the specs of the Q2 transistor on the GLX-PCB-PRO Hayward board? Or are there any detailed schematics online for board repair that may show the values or part number.

Unfortunately, this is a "good luck with that" situation. Pool controls are deeply proprietary, and the only supported means of repair is board swapping. Reverse engineering a good board is likely to be the only way forward unless you know a Hayward engineer and buy them some beers.

 

[MSchutzer]

While I don't have any schematics that looks like a SOT-23 packaged driver transistor, likely for the relay that has the burned hole on the one of the output terminals.

From your pictures I can see that the gate is terminal 1, pin 2 the source is likely ground, and pin 3 the drain likely runs off to one of the coil terminals of the relay (the top two holes in your photo). Your finger is covering up that trace that goes to pin 3 (the drain) so I can't see where it goes.

A general purpose N channel logic level FET such as the 2N7002 should work fine in that location. Typically the gate is driven by a 0 to 5 volt (or 0 to 3.3v) logic signal and that turns on the FET and connects the drain pin to ground, sending current through the relay coil.

https://www.digikey.com/short/vqp1d7qb

The real question is why did that driver part fail as the coil side of the relay should be isolated from output contacts. It looks like one of the relay output contacts burned up from maybe an over current condition on the load. Did the relay that you removed catch on fire? That would cause the insulation to burn off the coil side of the relay, causing a short across the coil, causing the relay driving transistor to fail and burn up from excess current.

 

[ajw22]

Let’s get @ogdento to have a look.

 

[ogdento]

i think @MSchutzer is on the right track... I don't have one of these to look at

 

[generessler]

A general purpose N channel logic level FET such as the 2N7002 should work fine in that location. Typically the gate is driven by a 0 to 5 volt (or 0 to 3.3v) logic signal and that turns on the FET and connects the drain pin to ground, sending current through the relay coil.

Very cool. I'm curious how you conclude it's an n-channel FET. My Jandy boards seem to be heavy in BJTs.

 

[MSchutzer]

I'm not absolutely sure, but I don't see any biasing resistors near the part that would be typical for a BJT. Logic level N channel FETs are very commonly used as a low side driver since the gate can be directly driven by from the logic. To know for sure you would have to trace back the pc board trace running to pin1 and see if there is a current limiting resistor in series with that trace. If there's a resistor there then it might be a NPN BJT also.

 

[mpjetta]

Thanks everyone for your help. I have a "parts board" coming from ebay and hopefully I can pull a part number of that good Q2 transistor to further narrow it down. Or I'll pull that transistor maybe if the parts board is really DoA. I'll order a few 2N7002s as well.

The real question is why did that driver part fail as the coil side of the relay should be isolated from output contacts. It looks like one of the relay output contacts burned up from maybe an over current condition on the load. Did the relay that you removed catch on fire? That would cause the insulation to burn off the coil side of the relay, causing a short across the coil, causing the relay driving transistor to fail and burn up from excess current.

I'm not sure if the relay caught on fire but it definitely melted good in one spot as seen in this picture.

I went back to my home assistant logs (I have the aqualogic integration) and cameras and nothing was out of the ordinary environment wise when the board switched from "OK" to the error condition. I was expecting maybe it happened right when the pump kicked on for the day or some surge during a lightning storm but it seems to have gone bad in the middle of a sunny afternoon.

Will update this thread when I have some more information.

 

[MSchutzer]

@mpjetta,

Did you see this post from today from someone with extra GLX-PCB boards that he is looking to get rid of?

GLX-PCB-MAIN Boards

Hello all, I recently upgraded my old Hayward Aqua-Logic system and now have 3 GLX-PCB-MAIN boards that I have no use for. As we know these boards are very expensive online. I know 2 of the 3 boards are in complete working order and the third will need to be verified. My question, does anyone...

www.troublefreepool.com

 

[generessler]

I went back to my home assistant logs (I have the aqualogic integration) and cameras and nothing was out of the ordinary environment wise when the board switched from "OK" to the error condition. I was expecting maybe it happened right when the pump kicked on for the day or some surge during a lightning storm but it seems to have gone bad in the middle of a sunny afternoon.

Not saying this is it, but my Jandy box blew up a rail-mounted relay (not on a board) when there was a weak and arcing 220vac connection elsewhere in the circuit. A guess is the arcing was causing inductive kicks that exceeded the contact capacity.

At any rate, there was lots of heat in your board relay. That could have caused a coil-to-ground short, which could certainly let the magic smoke out of a driver transistor.