The magnetic induction intensity of ordinary magnets is not high, which will not cause harm to human body. If you have been working in a certain part for a long time, it is still being studied, as mysterious as acupuncture, as if it is more mysterious than acupuncture. However, because the CRT is generated by scanning the electronic current deflected by the magnetic field, it interferes with the CRT.
The applied magnetic field will distort the magnetic field in the imaging tube, causing the electron flow to deviate from the normal scanning trajectory. Causes image distortion (black and white and color display) and color spots (color display only). The general multimedia speakers use magnetic shielding technology, and placing them next to the CRT will not cause any impact, but removing the speaker magnet and scanning the CRT will see obvious effects. However, it will not cause any damage to the service life of the CRT, at most it is only a long-term image distortion caused by a single point of burn.

If the image is still deformed after the magnet is removed, it is because the metal palette on the inner surface of the kinescope is magnetized. As long as the demagnetization function of the monitor is turned on and the demagnetization is removed, the old monitor needs to be turned on and off several times. For qualified hard drives, the magnetic shielding technology is quite high. You cannot destroy it from the outside by the magnetic field. Experts have calculated that if the magnetic field reaches this strength, it is enough to suck out all the iron in your body.
Floppy disks and tapes are what we should really pay attention to, but it is indeed who still uses floppy disks to manage their bank cards (with magnetic strips on them). For the motherboard or whatever, you don't need to be careful about what the bad consequences will be. A previous friend mentioned the problem of cell phone calls, not because of the magnetic field, but because of changes in the electromagnetic field. The constantly changing electromagnetic field radiates electromagnetic waves to the surrounding space, while the magnet generates a constant magnetic field and does not radiate electromagnetic waves outward. Needless to say, the current concepts of electromagnetic signals interfering with the electromagnetic compatibility of home appliances are mainly aimed at problems such as electromagnetic wave pollution to the power grid, not human health issues.
The phone is placed next to the recorder, which makes a lot of noise when making calls, much worse than a shortwave radio. As for the computer, I haven't tried it, nor have I seen it. One day we will try it. But I do n’t think it ’s anything unless the machine is too bad. The harm of microwave (high-frequency electromagnetic waves) to people all over the world is still being intensively studied. There are many standards for mobile phone radiation standards. However, if a person is exposed to a high-intensity electromagnetic field for a long time (note that this is a constantly changing electromagnetic field, not a constant magnetic field), he may cause cancer.
Now that the frequency of the CPU and the motherboard bus has entered the decimeter microwave band, those who open the cover and play for a long time should pay attention. In short, the magnet is very safe, don't be afraid, although microwave ovens can't be avoided, but also pay attention to it, try not to open the lid of the box, try to open, try to stay away, do not open to people.