Touchpad works "on its own" when the charger is connected

When the device is on the charger, the touch pad either does not respond or works as it pleases: the cursor is in the middle, one touch and the start menu or explorer for files opens …
While the device was on the charger, I was watching a movie on the internet (via wifi). When touching the touch pad, no reaction at first. With another touch, he started “working on his own”!
USB mouse worked normally!
Of course, this isn’t the first time the LapBook Pro has done this to me!
All updates are the latest.

I think it’s good for us to know that:

Every electronic equipment emits radio wave.
If its power is too strong, it interferes and inhibits other equipment’s proper working. This phenomenon is called “EMI” (double meaning… electro-magnetic interference / immunity). If you have a CRT monitor, put a magnet on a screen. Figures on the screen twist. That is EMI.

Therefore, almost countries in the world has the regulation related to EMI. For example, we can see FCC mark on CHUWI products. This mark indicates that “radio wave from this product is enough little to avoid EMI” in U.S.

We might keep electronic equipment which has strong radio emission, from working near sensitive equipment like sensors (touch screen, touch pad, antenna, …).


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Are you saying that the charger “bothers” him?
Since everything worked until I plugged in the charger. Without moving the laptop from its place, I plugged in the charger. Then the touch pad went crazy.

Might do. All depend on how equipment works.

Touch pad/screen detects capacitance change (or resistance change).
So a parrot tap with his/her beak, pad reacts.
Stylus pen emits radio wave and the antenna built in a screen receives it.
If something emits radio wave like stylus, pointer moves and is clicked.

I cannot imagine what EMI induces and what induces EMI.
If equipment does not have appropriate shield case, it easily emits radio wave.
e.g. if you use a long conductive(steel pipe, cable…), very long range radio emission can occur. It’s like a crazy surprise.

And, unfortunately, in some countries, EMI regulation is voluntary, not mandatory.

PS: When i was in a high school, I connected PC’s TV output to the steel pipe in reinforced concrete of school house. God may blessed me. I broadcasted my PC screen over the school. Of course, I was called by teachers. :smile:

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So, the cause could be the metal case of the laptop ?!

In general, metal shield works for prevention of radio emission, except it is connected to some kind of a electronic signal (*). So metal body is good for stop EM interference.

Under strong EMI, equipment works unintentionally, that is, random bit inversion in NVRAM, distortion of letters on a screen and so on, Rarely induces functioning like as intended. So I guess some kind of touch pad gesture, Windows steps recorder is triggered but not sure.
I have the experience that TouchPad of my Hi10X opens notification panel repeatedly unintentionally. I disabled TouchPad by device manager, but it never stopped (then I covered it with paper).

There may be some weakness around TouchPad device possibly.

(*)The reason why high-speed cables are metal-shielded is (1) guard signals on the cable from environmental EM field (2) prevent cable from working as an antenna. In general conductive works as an antenna when connected to signal source.

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Perhaps, since the problem of “disobedience/arbitrariness” of the touch pad occurs when the device works on a charger with wifi and bluetoth on, the problem is in their “quarrel” (maybe one neats the other too much), so there are disturbances that I “behavior” of the touch pad.

Let’s say I used it on a charger yesterday, but without the bluetooth on and there were no problems. That’s why I think that the “combination” of the included charger, wifi and bluetooth on “does not suit” him - it creates (electromagnetic?) Interference that manifests itself in the said way! So I think, perhaps, it is also a construction error?

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yep I also have this issue.
the problem became apparent after I purchased an aftermarket charger from aliexpress after the charger supplied with the lapbook stopped working (I suspect it had an internal broken wire in the cable).
The issue appears to be that the internal circuits of the charger are not grounded/earthed and that is causing distortion with the electrical signal. you can confirm this by using yourself as the ground, and touching the metal body of the lapbook (any metallic area beside the trackpad for instance) and you should notice the bouncing/movement of the cursor on screen stops. unfortunately there is no fix for this as its a charger design issue.