Small maintenance technique of optical mouse and analysis of common faults

The photoelectric mouse uses the photoelectric sensor to replace the mechanical element in the mechanical mouse, thus the maintenance method has the unique characteristic. Let's take a look at the optical mouse maintenance tips and common fault analysis Daquan. Optical mouse failure of more than 90% for disconnection, key touch bad, optical system dirty, a few inferior products are often virtual welding and component damage occurred.

Small maintenance technique of optical mouse and analysis of common faults

Cable Chip disconnected

USB Cable Line

Cable core circuit Breaker mainly displays as the cursor does not move or when good time is bad, uses the hand to push the line, the cursor jitter. General break fault occurs in the plug or cable leads to frequent bending of the end, at this time the sheath intact, from the appearance of the general can not see, and because of the disconnect at the time of disconnection, using a multimeter is also difficult to measure.

The processing method is: apart the mouse, the cable line plug from the circuit board, unplug, and according to the color of the core line and the corresponding relationship between the needle mark, and then the core line according to the location of the disconnection cut to 5cm~6cm about, if you have a hole-shaped pin and pressure line, you can press as it is, otherwise you can only use the welding method, The core wire is welded to the end of the hole-shaped pin.

In order to ensure that the cable is no longer due to fatigue and disconnection, it is advisable to waste ballpoint pen spring, to be cut to the core line will be the spring sleeve outside the line, and then weld good contacts. With the mouse top and bottom of the spring by the end of the head on the edge of the lid, so that most of the spring outside the mouse buffer, which can prolong the service life of cable.

Key failure

Fretting is the key part of the mouse button

First, Button wear. This is because the bar button on the micro-switch and the plastic cover of the bar button contact with a long time frequent friction, the measurement of micro-switch can be normal break, indicating that the micro-switch itself is not a problem.

Treatment method: Can be in the upper cover and bar button contact Place brush a layer of quick-drying adhesive solution, can also be affixed to a self-adhesive paper for emergency treatment.

Second, the key failure: The key failure for the micro-switch in the reed fracture or internal contact bad, this situation must be replaced by another button; for the specification of a special button switch, such as a temporary inability to find substitutes, you can consider will not use the key and left-click Exchange, the specific operation is: the use of electric soldering the left mouse, middle key, good mark, The removal of the key welding back to the left key position, the key switch must stick to the circuit board welding, otherwise the button will be higher than other buttons and cause feel discomfort, serious will lead to other keys and failure. In addition, the Mouse circuit board component welding is also likely to cause key failure, the most common situation is the solder on the circuit board for a long time by force and lead to fracture or off welding. This situation requires soldering with electric irons or connecting the broken circuit pins back to the good.

Sensitivity variation

Sensitivity variation is a common fault of optical mouse, specific performance for mobile mouse, the cursor unresponsive, do not listen to command. The reasons for the failure and solutions are:

One, light-emitting tube or photosensitive components aging: Optical mouse core IC internal integration has a constant current circuit, will be the working current of light-emitting tube constant in about 50mA, high-end mouse general use of intermittent sampling technology, sent out of the current is intermittent conduction (sampling frequency about 5KHz), The power of the luminous tube can be improved under the same power consumption, so the detection sensitivity is high. Some manufacturers in order to improve the sensitivity of the optical mouse, artificially increased the light-emitting diode operating current, increasing the launch function. This can lead to the early aging of light-emitting diodes. At the receiving end, if the quality of the photosensitive transistor is not high, the working time is long, will also natural aging, resulting in sensitivity to become worse. At this point, only the replacement model of the same light-emitting tube or photosensitive tube.

Lens

Second, the photoelectric receiver system offset, the focal length is not aligned. Optical Mouse is the use of internal two pairs of photoelectric detectors perpendicular to each other, with the photoelectric board to work. The light emitted from the light-emitting diode shines on the photoelectric board, after which the reflected light is reflected again through the reflector, adjusts the transmission path, receives the photosensitive tube, forms the pulse signal, and the number and phase of the pulse signal determines the speed and direction of the mouse movement. The transmitter and lens system components of the optical mouse are assembled in one, fixed on the mouse shell, and the photosensitive transistor is fixed on the circuit board, the location of the two must be quite accurate, the manufacturers are in the calibration position, with hot melt glue to the light-emitting tube fixed on the lens assembly, if the use of the process, the mouse was touched or vibration too large, It is possible to get the hot melt adhesive off and the light-emitting diode shift. If the light-emitting diode deviates from the calibration position, the light reflected from the photoelectric board may not reach the photosensitive tube. At this point, we have to patiently adjust the position of the light-emitting tube, so that it restores in situ, until the horizontal and vertical direction of movement, the pointer is the most sensitive, and then with a small amount of 502 glue fixed the position of the light-emitting tube, close the cover plate can be.

Third, the external light influence. In order to prevent the influence of external light, the bare part of the lens component is concealed by the opaque black paper, so that the light is transmitted in the black box, if the dark paper falls off, causing the external light to illuminate the photosensitive tube, it will make the photosensitive tube saturated, the data processing circuit can not get the correct signal, resulting in lower sensitivity.

Four, the lens path has the pollution, causes the light not to arrive smoothly. The reason is that the working environment is poor, there is pollution, long time, dirt attached to the light-emitting tube, photosensitive tube, lens and reflector surface, blocking the path of light access to light path. The treatment method is to use cotton ball dip anhydrous ethanol scrub, scrub parts including light-emitting tube, lenses and mirrors, photosensitive tube surface, to pay attention to anhydrous ethanol must be pure, otherwise the more clean the more dirty, can also be cleaned with anhydrous ethanol, alignment lenses and reflector slices, and then gently wipe with a clean cotton stick, until the smooth as ever.

Five, the photoelectric board wear or the position is not positive. Photoelectric mouse of the photoelectric board printed on a lot of black-and-white small lattice, light to black lattice when the black absorption, photosensitive transistor will not receive reflected light. On the contrary, if the white lattice, the photosensitive transistor can receive reflected light. When used, we should pay attention to keep the photoelectric board clean and good photosensitive state, while the mouse relative to the position of the photoelectric board, the position of the photoelectric board deflection or photoelectric plate wear is severe, it will make reflection of the light pulse deformation or blurred, the circuit will not be recognized and led to poor mouse sensitivity.

Mouse positioning is not allowed

Failure of the mouse position is erratic or often drift without cause, the main causes of failure are:

One, the external stray astigmatism influence. Now some mouse in order to pursue beautiful appearance of the light transmittance is too good, if the optical path shielding, coupled with strong light interference around, it is very easy to affect the mouse inside the transmission of light signals, and the resulting interference pulse will cause the mouse error action.

Second, the circuit has a virtual welding, the circuit generated by the pulse mixing caused interference, the normal work of the circuit has an impact. At this point, you need to carefully check the solder joints of the circuit, especially some of the vulnerable parts. After the virtual solder point is found, it can be mended by soldering iron.

Third, the crystal or IC quality is not good, affected by temperature, so that its operating frequency instability or drift, at this time, only with the same model, the same frequency of integrated circuits or crystal oscillator replacement.

Above maintenance Note: Many failures need to open the mouse shell to repair, at this point need to remove the screws at the bottom, if you remove the visible screws can not open the mouse, then do not pry, check the label or warranty affixed whether there are hidden screws, some mouse links there are plastic barb, demolition should be more careful.