Hi, I am trying to repair the touchpad of my Acer 532h netbook. There are a few things that I do not understand. Hope you can help me with this.
The original touchpad (Synaptics driver) did not work, it did not respond unless I used a wet finger. For a few years I didn't bother and used a mouse but now I got into the matter. I ordered a new touchpad with the exact same number on the internet (and crossed fingers) and now I am trying to get the replacement touchpad working. I carefully removed the old touchpad print first, it was glued to the backside of the palmrest.
the "defective" touchpad
First I did a test. I connect the new touchpad via the small buttonboard to the main board without the top cover/palmrest and without the keyboard and it works perfectly! To protect the circuitry I put a plastic foil between the touchpad assembly and the main board. So far so good.

But when I tape it firmly to the backside of the palmrest (I do not dare to remove the protective paper of the new touchpad yet), and then connect it to the main board and start the computer it shows the same behaviour as before: no response unless I use a wet finger. Is there a problem with the palmrest?
I went back to the first test to check the sensitivity of the touchpad. I put a stack of 2 plastic cards (like credit cards) on top of the touchpad and secured it with masking tape. Everything works fine. Even with irregular layers of carton and tape. No flaws here. So what causes the problem?
On the internet I found a few items about grounding the touchpad. I did some tests but they did not work.
So, attached tot the palmrest things don't work and I can't assemble the netbook now. Although the touchpad itself works all right even with 1.5-2 mm of plastic on top of it. I would really appreciate any comments on this. Thank you.