Locate hall effect sensor for disabling

We are wanting to use windows tablets in a high magnetic field. The problem we have encountered is the sensor used to detect a "smart cover" and shut off the screen is being triggered upon entered the field. I am wondering how best to go about locating the sensor in the circuit board and disabling.

For the sake of simplicity, I am comfortable enough to open the tablet (yes I understand this may void the warranty), dissemble any attached cables/components to access circuit board, and desolder the chip and jumper.

My question is how to detect where the sensor is located. I can pass a magnet around the tablet to identify the general area that triggers the screen shutoff/lock but need recommendations for how to locate the actual sensor.

Some of the tablets we are pursuing:

• HP 608 Pro G1
• Xiaomi MiPad 2

One cannot assume that the sensor is an integrated circuit; a small reed switch is often used. If you listen carefully, while probing with a magnet, you might hear it 'click' when your probe initiates a shutdown. Such reed switches look like glass tubes with a wire coming out each end.reed switches

Neither assume it is on a circuit board; for best sensitivity it is likely to be taped to the case, as close as can be managed to the landing zone of the magnet in the other half of the clamshell. And, in my MacBook Pro, that means it's behind the glass of the display.

I'm unfamiliar with smart covers on the specific models mentioned, but if you can localize the sensitive area, a soft steel plate might be cemented over that zone, to lessen the field gradient and desensitize the switch.