PS2 Logitech Wireless controller Left Stick won't centre

Hi. First post and great forum! I’m after some help with a PS2 Logitech wireless controller.

I noticed that the gamepad was permanently sending an “Up” signal to the PS2.

I found a utility for checking PS2 game pads functionality and found that the LH analogue thumbstick was not zeroing when it was in the centre. The values were off centre enough to be sending an “Up”.

Being no stranger to a bit of electronic repair and soldering, I ordered a replacement analogue stick and swapped the left analogue stick module out. I thought that this would solve the problem but unfortunately it still has the same issue when I checked it with the utility again.

The utility also shows the RH stick as being slightly off, but not enough to trigger a RH movement on the PS2.

So is there anything else I can try / swap out. Could it be something to do with the biasing of the voltages going to the analogue sticks? I noticed a small wet cap in between the thumbsticks and as this gamepad has to be at least 10 to 15 years old, I was considering swapping that out next?

I have bought another cheap wireless gamepad, but its nowhere near as slick and comfortable as the Logitech one, and to replace that costs around £50 for a second hand one on eBay.

Try checking the D-Pad and trace from there. Maybe there is a short. I had a shorted diode one time that cause a similar issue with another controller.
It may help if you can submit some pictures if you get stuck.