[Help] No display on Maldives Hydrojet Pro (S200102)

[PentaSX]

Hello,

I’m trying to connect my Maldives Hydrojet Pro (pump model S200102) with the PCB_V2B.

I followed the assembly instructions:

• used the red 8-channel bidirectional level converter,
• added the recommended resistors and capacitors,
• and configured the hardware in 6-wire mode.

Here’s the situation:

When I connect the module to the spa, the spa display doesn’t start.
If I touch the spa buttons, I hear sounds but the screen remains off.
The web interface of ESP is accessible without issue throught my router.

I previously tested the error bypass by connecting both connectors together from the web page, and it worked.

Connect the cables now!
Starting test in 10 seconds...

Connect the cables now!
Starting test in 9 seconds...

Connect the cables now!
Starting test in 8 seconds...

Connect the cables now!
Starting test in 7 seconds...

Connect the cables now!
Starting test in 6 seconds...

Connect the cables now!
Starting test in 5 seconds...

Connect the cables now!
Starting test in 4 seconds...

Connect the cables now!
Starting test in 3 seconds...

Connect the cables now!
Starting test in 2 seconds...

Connect the cables now!
Starting test in 1 seconds...
Start test. Seq begins with HIGH, then alters.

Sending on D1, receiving on D6
---------------------------------------------------------------------------------------------------- // 0 errors out of 100
Sending on D2, receiving on D4
---------------------------------------------------------------------------------------------------- // 0 errors out of 100
Sending on D5, receiving on D3
---------------------------------------------------------------------------------------------------- // 0 errors out of 100
Sending on D6, receiving on D1
---------------------------------------------------------------------------------------------------- // 0 errors out of 100
Sending on D4, receiving on D2
---------------------------------------------------------------------------------------------------- // 0 errors out of 100
Sending on D3, receiving on D5
---------------------------------------------------------------------------------------------------- // 0 errors out of 100
End of test!
"1" or "0" indicates ERROR, depending on test state. "-" is good.
Switching cio pins 5s HIGH -> 5s LOW -> input
then DSP pins 5s HIGH -> 5s LOW -> input, repeating
Disconnect cables then reset chip when done!

I grabbed traces but I’m not sure how to investigate them further.

debug.log

gpioregister.log

Some extra details:

• With the module connected only via USB, everything works fine (I can connect to the web interface).
• With the spa connected, the web interface is accessible and show “ABC” displayed at the top, I could not control anything
• I left the default pinout

Firmware: 2025-06-02-0910
Model: MALDIVES2021
RSSI: -63

I checked all solder joints with a multimeter.
I’m not an expert at soldering, but continuity is OK.

I saw issue #issue 330 which looks related, but I couldn’t find a working solution there.

I would really appreciate any help or hints to move forward.
I’m available to provide logs, extra tests, or make adjustments if needed.

Thanks in advance for your support!

[PentaSX]

I just took a look at Release Notes...
It seems to be compatible with new model 200102 since v4.0.0
I just flashed dev branch now i've got the firmware version 2025-09-05-1055 right now.

Edit 1:
It is still the same, no display at all.
When i push the power button on the display, it makes a weird sound and nothing happens.
Thanks

Edit 2:
I made another test wirhtout cap and resistors, it is now working perfectly !!!

Here's my modification on the board !

[visualapproach]

Lovely!